Nahtan

Guess my son a while back had installed Forge and some mods. How do I get rid of the old Forge and mods?

I have a new install of Minecraft 1.12.1. It works fine. Then I installed Forge. When I open using the Forge version from the launcher, I get the "An unexpected issue occurred and the game has crashed" message. I've Googled and Googled, but no luck so far. I'm new to Minecraft and trying to set this up for my daughter. Running Windows 10. Here's my log: