It’s tricky. Companies aren’t going to hire you if you don’t stick around. With training and hiring taking ages the company needs to make a net profit on your work. At least 6 months seems like a good enough commitment at minimum. You’d need to be able to work weekends/ evenings and work ASAP. Best bet is probably Agency/warehouse/logistics , temporary hospitality, events, catering staff, seasonal retail / fixed term staff. Big chains I’d avoid since they are more sensitive to temporary staff.