Found a virus, now what?

I ran a full system scan and found a virus. Now I’m not sure how to remove it or quarantine it. I have the free version and have the options to:

Repair
Delete
Move
Finder
Export

I already deleted it…so do I export it now? My mac has been running extremely slow and I’m not sure if it’s because the virus is still active on my laptop or because I downloaded Avast. I’ve heard from other users that when they downloaded Avast, their computer began to run very slowly.

Please advise next steps…thanks!