Ugdhar

Almost any beginning java tutorial will help. Google "beginning java tutorial", and pick any of the first ones that pop up that are not advertisements, and they will likely help. You will also need an IDE, the 2 most popular are intellij IDEA and Eclipse. It will not be easy, you will not begin right away with making mods or cool flashy java programs. You will be making a lot of lame calculators and name lookup things and console based stuff in order to learn things like syntax, keywords, classes/objects/OOP, scope, the list is too exhausting to cover here. I can promise almost every programmer here has made a bunch of a throwaway programs/code snippets, never to be used or thought of again, between when they began programming and now. It's part of the learning process! I would study and practice basic Java for at least a week. Then, look for a forge tutorial, McJty has good ones https://wiki.mcjty.eu/modding/index.php?title=YouTube-1.14. See if you understand the Java concepts being described, if not, make notes of what you don't understand, and dive back into Java tutorials. Also once you understand basic/intermediate Java, you can look at the vanilla source code, and see how they do things, for examples for your own projects. And if you have questions about forge (not basic Java), you can find answers here, you just need to post your code (get a github account if you don't have one, and learn how to use it), logs (debug.log is always a must for anything that runs but crashes/doesn't work), and a good explanation of what you are trying to do (from the end user/player perspective).

I would update Java, I think vanilla even ships with a newer version than this one

I only work with recent versions, sorry, so I won't be of any help with 1.12. 1.12 is no longer supported, you should update to a modern supported version. The LTS link at the top of every page has information on supported versions.

Well, if you don't provide more information, no one can help you. The information you have provided doesn't give ANYTHING to go on lol. Just post your build.gradle, since it's obviously broken?

I would say probably post build.gradle since that's the file it's yelling about

You need to have Java installed. If not, you can get it from https://adoptopenjdk.net/,get the Java 8 hotspot. If you do have java installed, then likely something hijacked the jar file association, google jarfix, get it and run it, and it should correct it. If you did not have java, you won't need to do this after installing java fresh.

What version is this for?

Unfortunately, I do not believe MCreator is supported here. Most of the folks here use straight up Java for making mods. You would probably have better luck asking on an MCreator forum (not sure if they have one, but they should!) It would take time, but my suggestion would be to learn Java (google "learn java" or "beginning java tutorials"), which will allow you to get the most out of forge modding.

Also, you probably want to download the forge installer, not the launcher.

Really old versions are no longer supported. Please update to a modern version (1.14.4/1.15.2) to receive support. More information on supported versions can be found in the LTS link at the top of every page.

It will be in the logs folder of your minecraft folder, which by default in Windows is %APPDATA%\.minecraft Also, to save you time and effort, make sure this is for version 1.14+, as older versions are no longer supported.

I do not know how to do it myself, I haven't had the need to yet, but: Look through the vanilla sources in the places where you've seen it happen (for a block or item or whatever it was that you saw), and see if you can do it in the same way. The vanilla source shows how to do all kinds of things

In the launcher, you can create new installations, and tell it to use a different folder, and give it a different version of minecraft and/or forge to use. Just click Installations at the top, and play around with making a new one until you figure it out, it's pretty easy when you start messing with it

That looks like the debug.log to me! Try removing vanillafix, it is for 1.12 as far as I can tell looking at curseforge.

Make sure you have Java installed, I would use Java 8 If you definitely have it installed, google jarfix and run that, it looks like Internet Exploder has hijacked your jar file association.

I don't have skype, sorry. If you can post it on youtube or something you can post a link to it here. Alternatively, you could share exactly what it says on the screen, it might help.

Are you new to modding, or new to Java? Overriding a method is very basic Java/OOP. If you are new to Java, then unless you are well versed in a similar language, you will have a Bad Time trying to mod. If this is the case, I would strongly advise looking up learning java on google, and start small.

Please provide more details. What did you download? Where did you download it from? Can you show a screenshot of what you are talking about?

Please post your debug.log (you will likely have to put it somewhere like a github gist or pastebin or something and link to it here), it is in the logs folder of your minecraft game folder (defaults to %APPDATA%\.minecraft)

Sorry, old versions are no longer supported here. You will need to update to a modern version to receive support. More information on supported versions can be found in the LTS link at the top of every page.

I think this is caused by someone breaking the mappings on 5/26 by naming 2 fields the same thing. I had the same problem, and finally opened up that AudioStreamBuffer.java file, and found an int and a ByteBuffer both named buffer. Try using 20200525 for your mappings. *edit: confirmed that this was a mappings glitch, should be fixed in 20200528, use 20200525 until then if you can't wait

Well, I don't think that's the full log, but it's for 1.12.2, which is no longer supported due to age.

The problem is you are specifying the folder your java installation is in, not the java.exe. find the java.exe (it's probably in the bin folder), and use the full path to that inside the quotes.

Post his debug.log, it will show where they are being loaded from