So I'm about to attend a major anti-racism protest in the next few days and have no idea how to prepare myself...

Anti-racist protests generally go well. Don't be too worried by what happened. It is generally only dangerous when racists and anti-racists begin to clash.

Smashies in this thread are a shame. this is the only good post.

I don't see any smashies here.

Sounds like smashies idiocy to me.
like a said here, use this a rectuitment tool for something more serious

Goggles to protect from mace.water balloons filled with paint are effective against police riot shields.

Good to know.

Should I bring milk?

Or gloves?

Foaming long-range wasp spray for the Neo Not-See's.

Yes, you should get a local lawyer on retainer.