If you're in the US, a recommendation is to look up your local CERT[0] organization - they usually have free or low cost classes and other learning opportunities. Triage is an important part, as is preparing for disasters that are relevant for your community. Going further, a basic first aid and/or CPR class is good to get hands-on.
(1) https://notendur.hi.is/thorsj/gogn/TNCC.pdf