I was in a similar position around 1.5 years ago. What helped me was:
1. Reaching out to people on X sharing that i just moved, would love to meet with offering some ideas where i can add value.
2. 1-2 meetups initially via luma/partiful. Most of them are noisy but even if you meet 1-2 good people that leads to long term connections.
3. Signing up for hobby classes - Most of the people in SF are in tech so you end up meeting a lot of like minded folks.
4. Going to popular coffee shops/coworking to work. Serendipitous encounters are easy to happen here.
Good luck!