I've just started a job at a restaurant a few days ago and now I'm going to an interview for an assembly job in a sheet metal shop, which corresponds to my trade. I'll definitely take the shop job over dishwashing, but I don't want to go out on bad terms. I've never been in this kind of situation before, what do I do?

Go on the interview. If the tell the shop that you currently have a job but still want to interview. If they want you they will compromise to interview you etc.

If you get the job let the dishwashers society know and do two weeks or less if they are cool.

My last job guilted me into two weeks, but everyone I interviewed with knew I was employed and respected my honesty.

I'm going to the interview, without any doubt. I don't have any problem with working a couple of weeks extra at dishwashing if I'll be eventually doing what I want to do. I guess it's not really that difficult, I just have to tell the right people I'll be moving on.