I need some advice! Help!

The last time I worked was in 2020. Me and my 3 children did receive stimulus checks and recovery rebate credit when I filed last year. I also got the monthly advance credits because they went off of my 2020 tax year. My income all of last year was only the monthly credits. I’ve never filed without an income or w2 before, but I was told that people do file that way. So I’m wondering if I should file that way and if I would be getting the remaining amount of the advanced credit, would I get any other credits? Any advice from someone who knows about this would be greatly appreciated! Thank you!