I’ve been doing a bit of this for a while now. I wouldn’t really bother doing physical releases unless you are planning on doing a string of shows (a tour, or sporadic dates - as long as they’re not all in the same town!). This is because distributing your own physical stuff around is a full time job in itself and for DIY type acts I find most shops will only do sale or return. So if you do get loads of stuff stocked, it’s a lot of work to keep on top of where it is and chasing up to see if it’s sold. Of course, people do buy physical stuff direct, but not much compared to off the merch table in my experience (unless you’ve got shit loads of press or someone working for you).
Physical formats are the best though. I’ve always been a bit underwhelmed by tape and 7" sales (even though I personally love these formats and they’re quite affordable up front). CDs seemed to do consistently well until last year for me. But 12" LPs do the best, I’ve found - but it’s a big outlay if you haven’t at least got a lil label helping you out. I also use Bandcamp (it’s the best!). And Tunecore for digital distribution to Spotify etc (good for promo imo).
Re: press. Find writers who write about similar artists and contact them direct if you can. Same goes for radio shows and podcasts.
Ultimately, the best thing when you’re doing it alone is to try and engender a community. Talk to other acts doing similar stuff. Put them on in your town. Engage in dialogue with folks who buy your stuff or come to your shows. Collab. with people on splits and mixes etc. Send people bonus materials and gifts (zines, badges) if they buy direct. Ask other similar acts if they wanna swap CDs/albums etc.
DIY for me isn’t just booking my own shows or making my own albums, it’s kind of the creation of a whole world. It’s great. Make a narrative. Make a label. Invent a genre. It is a great time to be a DIY musician