Lookalike vs retargeting

Lookalike audience vs retargeting

Hey so I’ve been running interest targeting ads

I finally caught the hang of that. I make a few sales here and there

I test many different adsets at $3 a day each.

So what’s the difference between retargeting ads and lookalike ads?

And when do I start to implement those

Do I need a certain amount of purchases or impressions?