If you're only trying to install and run mods, I'd highly recommend the Twitch App. This is what I use when I actually want to PLAY minecraft, not break it.
"Create Custom Profile" is the button to click if all the mods you want aren't already a modpack. When you install mods from the provided ones, it handles all the forge installation, dependencies, etc., and you can always add mods that Twitch/Curse doesn't offer to the mods folder that Twitch creates (on mac it's in Documents/Curse/Minecraft/Instances...).