If you live near the Ukrainian borders, then you can help refugees who are seeking shelter, though i hope that the bordering countries is organizing right now.
Military aid as an individual makes no sense and going to Ukraine to fight a superpower will have very little effect.
Then i suppose you can send money to help Ukraine, though i have no links to any good support channels.
My own help at the individual level is raising awareness of what is going on, and trying to influence those who are in charge.
Disinformation is very much a problem in raising awareness, you want to make sure you are promoting a true story and not a made-up one.
Some good examples of this can be found here: https://www.bellingcat.com/news/2022/02/23/documenting-and-d...