Solo local volunteer opportunities / ideas?

I would like to start doing some more local volunteering. The problem is, I have zero social skills and showing up to an event / working with an organization terrifies me and makes me feel physically uncomfortable. What could I do, by myself, that would make an impact in the area? Think a few hours on the weekend or after work (next spring/summer when there’s more daylight). All I can think of is trash cleanup; anyone else have good ideas?

[EDIT] Just finished responding to each top-level reply. Thanks for the ideas. Some of them won’t work out for one reason or another (mostly time; I work a normal 8-5 so I can only do weeknight or weekend hours); for all the others I’ll reach out in the next few days/first week of January and see which organizations need help.