I would highly recommend checking out the programs at Holiday Park. They do round robins on Friday evening and Sunday afternoon as well as clinics during the week. Have great pros to hit with at a reasonable price.
Sandye, email me and I will ask my local friends if you can join them on Friday evening and Monday afternoons for tennis. They just get together, play then pop a beer. They are my long time friends from ... the ski association! The level of play is well, friendly.
Friday is Hickam AFB, Monday is Keehi lagoon courts.
I agree it's hard to find a drop in workout or mixer. I love those 'cause I'm very bad at arranging games. The DH courts are a good bet - show up early and ask around. Sorry to hear they have become run down and the city has no money to fix them up.
Aloha Sandye! You are approaching this correctly. Others now now your timing, level, and interest. Hopefully, someone will respond that works as a tennis partner. The public courts do have a fair number of drop in players looking for matches as well. Mahalo nui loa for joining and I hope you find some great tennis! Dan