Americans, if you have not done first aid training in the last five years, I strongly recommend getting a refresher now, and starting to carry a trauma kit with you when you leave the house.

It looks like most of the US Red Cross first aid courses are very superficial, so you'll have to go digging for local resources. The syllabus I recommend is the one offered by the UK and most EU Red Cross groups, including their optimal mental health response unit, and ideally something on using Narcan and Epi pens. You can find it here: https://www.redcrossfirstaidtraining.co.uk/courses/first-aid-training/first-aid-at-work/

If you're piecing together a course from other offerings, you definitely want to make sure that you're doing CPR basics, massive hemorrhage/bleed stop, and shock/stroke at least. If you can find a trainer who can also add to the UK curriculum a treatment protocol for tear gas and pepper spray, that's great. You're going to receive a ton of information in these courses, so please take good notes (and hopefully you'll get the training slides to take home). Make up your own cheat sheets for the core diagnostic procedures — ADCDE/MARCH, AVPU etc. and keep them in your kit. Better yet, also go with some friends — it's always more fun that way and you'll retain more when you're comfortable and having fun — and then spend an evening every month or so going through some basic drills to keep each other fresh.