I am a noob...

I installed Avast and I tried to do the stuff I usually do and it keeps stopping my flashplayer from being used… how do i fix it?

avast doesn’t block, but scans and alerts if infection is found.

Can you be more detailed are you getting any errors ?
What flash player ?
Can you explain exactly what you were doing, to me a flash player works inside your browser and I assume this isn’t the case with you.