This sucks! I'm so sorry to hear man. I've spent a lot of time with people who are homeless, which has caused me to think about this very question though I haven't had to put any of this into practice so grain of salt.

- Get a membership to a cheap gym so you can use their shower (and potentially wifi) if the shelter doesn't work out. In many areas it's possible to get a membership for $10-20/month. Clean your clothes in the shower with you.

- Try really hard not to feel desperate during interviews. We make worse decisions when desperate. Easier said than done :(

- You may need to buy a laptop, which will suck, but hopefully you can find something good enough and very cheap on Craigslist? If you can't get a laptop, consider public library or internet cafes (if those exist there).

- Food is going to be tough. Canned beans will become a close friend. Also canned soups/stews. Peanut butter, cheap produce. You may be able to find edible plants nearby. Free samples at grocery stores? Bulk sunflower seeds are cheap. Lifted most of these food ideas from a thread on reddit btw.