A little confused as to whether the truck has been purchased already or not. In any case that seems to be an awful large vehichle to be be the daily around town get groceries type vehicle.
Why put the wear & tear on it for around town errands?
I'd be looking for something small & cheap to run for the local vehicle. Something along the lines of a Honda Fit, or many others similar.
For the truck, well that is governed by the trailer size. If the plan is to live in it for a year straight 30' or less will get real small real fast. Go much over 30' & you are into 1 ton trucks if you want to feel comfortable in being well under weight specs & not doing all kinds of mods to make up for stock truck limits.
Lots of numbers to juggle. Get a used car cheap now & put saved money towards a more capable truck & larger trailer later?