Crash Everytime the Game Starts

I try to go onto 1.12.2 and the Mojang screen doesn't even fill the monitor. When I go on 1.14.1, the Mojang screen fills the monitor, but it stops loading at a small amount. I let it be for hours, and it stayed the same, both versions. When I click, every single pop-up for a crash shows up. Please fix!!!!