MailChimp integration for nonprofit

Hi everybody,

I’m the board of a nonprofit and we’re moving from BootStrap to Wix and I wish to capture email addresses for our email newsletter and wish to connect our MailChimp account. As we’re a nonprofit and just starting, dollars are very tight so what’s the “best free” way to do this? Bonus question: would like a timed pop up too!

Alternately - should we simply move our MailChimp list to Wix (sub 200 right now) and run things from there? Is the Wix email marketing system decent? (never used it)

Thanks!