Launcher misfire when adding mods?? ?

[typoAdventure]

I'm a first time mod user and rather dumb when it comes to software, so please explain in little-kid language so that I can understand.

 

I downloaded and installed Forge 1.11.2 first. I tested it by opening Minecraft in the Forge profile (I think that's what it's called, the thing on the launcher where you select Forge?) and it works fine. Then I realized that the mods I want are all 1.7 and 1.8, so I also downloaded a previous version of Forge - 1.7.2-10.12.2.1121. That Forge works ok too, but only by itself. When I drag any mod I want into the mod folder, the launcher works fine, but the game never comes up. I don't even see a crash message.

 

I read the rules, so I would post a crash report if I could find one. I'm not sure there even is one. I'm trying my best, but I don't know what I'm doing. I realize there is probably a really easy fix for this, but I don't know what it is. Help?

[typoAdventure]

Also, I'm interested in this:

Quote

• It is highly recommended you run any modded versions in separate folders using the GameDirectory setting in the vanilla launcher. This will store all your save files, configs, mods, etc. in whatever folder you specify (instead of just .minecraft) so they do not interfere with your vanilla installation (or other modded versions you may have installed) and vice versa. To set it, click "Edit Profile" in your launcher and in the settings screen that pops up, modify the "Game Directory" setting (Screenshot).

I don't know how to do that unless it's manually shifting/copying files from OfficialMinecraftFolder(A) to AFolderICreated(B).

[typoAdventure]

Where is the Game Directory setting?