Here are a few suggestions.

Schools, particularly primary schools (K-8, K-6, K-5 depending upon your local school system). They like musicians who can get kids involved, and they especially like those who can offer a thematic program depending on the time of the year. Speak with the principal or the head music teacher.

Retirement communities. The people are healthier than in nursing homes. Old standards go over well. So do pop songs, early rock and roll (Teenager in Love, Dream, Rock Around the Clock, etc.), even Beatles songs, Kingston Trio, and Peter, Paul, and Mary stuff. Old spirituals and gospel songs (Joshua F'it the Battle of Jericho, Down by the Riverside, When the Saints Go Marching In, etc.) are always welcome. Depending on the ethnicity, so do Yiddish songs, Irish songs (the sentimental kind, not the rebel songs), Italian songs, etc., if you really know any. Don't fake it. Speak with the program director or the social director.

Senior citizens centers, Elderhostel programs, retiree chapters of unions. Same as above.

Public libraries. They love thematic programs, either seasonal or historical. Speak with the program director.

Museums, especially smaller museums. Similar to public libraries.

YMCAs/YWCAs. Also similar to public libraries.

Civic associations, benevolent associations, lodges, church fellowships. Also similar to libraries. Speak with the program director or the social director.