my minecraft in 1.8, crashs and gets stuck on "building terrain" and 1.12, wont even load!

i like to play on 1.8 for better pvp, but i would play on 1.12 so a MOD told me go on 1.12. Soon as i did that it just stays on the MOJANG screen, and has been there the last 5 minuets! please help, i will link the 1.8 crash report, and the 1.12. But i have not been able to play minecraft so please help! no version works for me, and i bought this game and if i am unable to play it, give me my money back. Fix it.