An associates degree is not enough to get a work visa here. That's the main priority you need to set. If you don't even know what sort of job you want, yet you dream (and I write that word with the heaviest of sarcasm) of living here, think again. It's hard enough to live in your own country with no career goals, but in a foreign land, you can't do that.
You're going to need an education of at least a bachelor's degree, plus a hefty dose of Japanese language skills (reading/writing/speaking). Even work in a hostel will require something like those 2 things, if for no other reason than the visa.
Do it right the first time.