what's a good toy for a beginner bottom?

Start with something on the smaller side so you can get used to it. Like not something so small that it's not pleasurable but don't be a hero on your very first try. Once you get comfortable you can buy something bigger and keep the original as a warm-up toy. Plug or dildo works, basic toys are usually pretty affordable so you can try one of each. Whatever toy you choose make sure it has flared bottom. Silicone is a good body safe material for anal play but glass or metal are options if you want to try something firmer. Don't use silicon lube if you're getting a silicon toy; use water-based lube. You can get condoms so you have less to clean afterwards but obvs that's more cost. Clean every time with soap and water and sanitize often. Method depends on the material; if it's not battery-powered and it's one of the materials I mentioned earlier you can boil for 10 mins. If you get something fancier it usually comes with instructions for care. Oh and if you see a tear in the silicone flare base or a crack in the glass, that toy is done and you need to throw it away immediately.

Sorry if I'm repeating any info you already know, I just wanted to cover everything I could think of.

If it worries you, you can do what i do, and get it ordered online with discrete shipping.

Either way, while I'm still an eggy boymoder, it sounds and seems like most of us tend to feel more confident once you're out and living as your true gender. I can't tell you how you'll feel, but hopefully once you start to feel the comfort provided by gender euphoria, you'll start to feel good enough about yourself to not feel wrong for enjoying sex, which is completely natural, valid, and okay.

I’m lucky to really not care, but honestly buying a sex toy in person sounds a lot more scary than just wearing a skirt.

think the vibe would be less weird if I went to a sex shop

Maybe but you are probably gonna be perceived as a sexual being in there. Staff are unlikely to be sex negative but if you're shy, the enthusiasm can be scary if they're one of those types.

I literally might just die of a heart attack the first time I try to go out wearing feminine clothes. I guess it wouldn’t be the worst way to die lol

Maybe try small steps at a time. Like, relatively neutral clothes with fem accessories?

Or alternatively, go all in, but in a costume so there's a bit more disconnect with it? At least for me, that felt like a much less big deal (even with small, but noticable breast forms), even with meeting up with my sister and a few other people whom I'm still not out to. But my goal wasn't to get use to dressing that way and I'm not sure how much its helped with being comfortable dressing like that outside of costume. .

You can get smaller toys for beginners, some places will have a beginners section also depending on what you want you can get various types of vibrators or wands too.