I am absolutely an advocate for leftists and members of vulnerable demographics responsibly arming themselves and forming community aid groups, but I would strongly encourage you not to go purposefully putting yourself in dangerous situations. That's how you end up with situations like the Rittenhouse shootings, or worse (from your perspective at least) end up dead in a confrontation that didn't need to happen, whether from armed fascists or the police. There's nothing wrong with stocking up on ammo just in case **** really hits the fan, but I strongly advocate against open carrying at protests unless part of an organized group doing an armed demonstration.
If you aren't already a member, I would recommend trying to find an join a local left-leaning LGBTQ+/BIPOC-friendly firearms/community aid group. I'm a member of the Massachusetts branch of the Socialist Rifle Association and can absolutely vouch for them as an invaluable source of support, training, and other resources without the usual gun culture bullshit that comes attached to right-wing gun groups. The John Brown Gun Club/Redneck Revolt, Pink Pistols, Project Blazing Sword, Huey P. Newton Gun Club, Latino Rifle Association, and Armed Equality are other groups I've heard positive things about from leftist friends.