ok so i went to do something basic today and tried to change my spark plugs. i went through 3 of 4 just fine. on the 4th i pulled it out no problem but when i went to put the new one it i couldn't do it. i'm sure i've made the problem worse by trying so many times but now i think i've messed up the threads pretty bad in the engine. the spark plug feels like it just drops down all the way and will start to cath but doesn't. how can i fix this? or can't i do it myself? thanks guys

Do you mean it won't tighten or you can start to screw it in?

I would try putting that spark plug in 1 of the 1st 3 you did to make sure it's not just a messed up spark plug.

I concur.