See who is a current member, who has lapsed and who never finished paying, and email last year's members to renew.
Members, under Memberships, is the roll: everyone across every membership year, with how many are current, how many have lapsed, how many started and never paid, and how much is still to collect. Search it, and Download CSV for the committee.
The Renewals tab compares two years: pick the year they held and the year they should have taken out. It lists who has Renewed, who is New this year, and who has Not renewed.
Ask them to renew sends each person who has not renewed one email from you, with a link to the new year. Somebody who has started joining and not paid counts as back, so they are not chased. An address that has bounced or reported us as spam is never written to again.