Question about what to wear to shabbos service

I am going to an Orthodox service for the first time tomorrow. I have health problems that stopped me from working almost all year so I don’t have disposable income and I don’t have a dress/skirt.

Obviously, I’m at the very beginning of the conversion process and mostly just looking into it. Even though I’ve been reading about it for a few months now and try to at least observe shabbos at home. I don’t want to offend anyone or come off disrespectful. I pretty much only own jeans right now. I’ve been sick and didn’t have a chance to go to good will for anything, but I don’t want the rabbi to think I’m not serious about attending service. I had to miss last week because I was sick.

I also don’t know if I should cover my hair.

Should I just email the rabbi and tell him why I’m not able to come until next week? He said that it wouldn’t be disrespectful if I drive since I live an hour away. I don’t want him to think I’m just making up excuses since I didn’t think to mention what to wear when I was talking to him.

I’m really nervous and I’m socially awkward anyway. I seem to screw up wherever I go and I can’t usually figure out why so I’m extra nervous about this. Especially since I am not bringing anyone and when I go to a new place for the first time my niece usually accompanies me so I feel less anxious. I thought about bringing my service dog, but he’s still kind of new and because I’ve been sick most of the month he hasn’t had exercise or been anywhere so he’s kinda rusty. I also don’t really want to bring him until I tell the rabbi anyway. He usually draws attention because he’s handsome and fairly big, when that’s the exact opposite of what I want. I’d much rather just be invisible tomorrow. I know once I go a couple times I’ll feel fine. And I know I’ll mess up at some point. I just don’t want to offend anyone.

Any advice would be greatly appreciated.