Help with facebook ads

Hi all,

I am running facebook campaign for my shopify dropshipping store and I got around 20 conversions on main campaign and 7 conversions on retargeting campaign which is fine, my budget at the moment is around 120 USD for main campaign and 50 USD for retargeting.

I feel that it is time to increase budget and go all in but I am not sure how much to increase. Can I increase the budghet by 100 USD for my maind ad or would it be too steep? Any advice?

Also how many website purchases do I need to create solid look a like audience 500 or 1000?

When i created audience for retargeting I chose all visitors in last 30 days, should I update this audience every week or it happens automatically?

Thanks.