June group bday ideas

Trying to plan my early 20s birthday weekend in June and having a hard time deciding activities! Would love to spend time outdoors - maybe hiking, beach, camping, etc! 15-20 ppl and don’t want to spend crazy money… not sure if overnight or day trips or staying local. Have lots of access to cars

Things I am considering
- Russian River (hike / float the river)
- Santa Cruz day (hike / beach / bonfire)
- white water rafting ? (+ camping??)
- camping in general (not sure anything available)
- day/overnight trip somewhere else??

Would love to hear ideas:)