foreign life insurance required forms

Hi I have foreign life insurance since 2017,  I am paying premium and have very little cash value. I have following questions

1, I didn't file720 because I didn't know I need to. how can I catch up previous years exercise TAX?

2, My combined foreign asset is less than $300,000 for married file jointly, so I don't need to file 8938, right?

3, Do I need to file form 8621?

4, Do I need to file 3520?

thanks