You're probably best off looking at joining a temp agency/recruiter and working in temp positions, since those are basically "at will" and you can stop working without any notice period without any repercussions. They are also convenient as they can sometimes be more flexible with hours - also typically agencies pay you weekly which is nice if you're only working for a short period.
For non-temp work you would normally be expected to work a notice period, how long depends on your contract terms (albeit during probation which is the first few months usually, it's typically just a week or two). In theory you could NOT work that, but you probably wouldn't be able to call upon that job for a reference in future if so...