Reinstalled Minecraft and it's working now. I think it had something to do with where I had the .minecraft folder (it wasn't in its usual place). It's crashing now but that's a problem with the single mod I had installed, not with Forge itself.
Alright, so I'm encountering a rather odd problem with Forge that nothing I've found could help me fix. (not using the newer version for compatibility reasons, by the way)
So I run Minecraft on the Forge version (1.7.10), and the game runs normally with Forge running as it should- except none of my mods load. No blackscreen, no crash, no error log (that I could find), nothing. Just no mods other than the base three. Very odd.
I tried it with all my mods from my old computer and I tried it with only one new mod, and had no luck. I also tried deleting my Forge versions and reinstalling Forge from scratch- that didn't work either. I have no idea what the issue here is and am very confused.
Wasn't having this problem on my old Windows 8 laptop, by the way- mods loaded just fine there. My new computer runs Windows 10.