Garage is built-need advice on electrical solution

Good evening all,

Apologies if this topic has been discussed many many times but I'm new to the forum and have very little experience with electrical.

My detached garage/guest house structure is now built. It is a new 20x24 wood frame Amish built garage that I intend to split down the middle. 1/2 will be a single-car garage and the other half (long-axis) will eventually serve as a single bedroom and bathroom.

It's located about 160 feet (including turns, bends, etc) from the main panel in the cellar of the primary house.

As I'll be doing the groundwork myself for the sewer and water supply plumbing, I'd like to also bury the electrical cable in the same trench. My intent is to bury the cable/conduit and have an electrician come out later as funds are available to make the connections at both ends with the appropriate sub-panels, etc.

My question is this: what size/type wire and conduit does the forum recommend?

Some considerations for power consumption:

1) the 'guest house' side of the structure will be about 220 sf and will include the standard light fixtures, power receptacles, etc together with a bathroom. I may have a small fridge in there as well. The largest power draw I can think of will be a mini-split type HVAC system. I'm sure some guests will occasionally use a hair dryer but again, nothing major.

2) the 'garage' side will include the standard light fixtures, receptacles, etc but the main power draw will be the occasional use of a 220v air compressor that'll support a blast cabinet that I'll use for small car parts. I don't see the need to runt the HVAC and compressor at the same time as when guests are staying over, I'll likely not be out there bead blasting car parts.

I understand copper to be better than aluminum but beyond that, I'm clueless.

I live in Northern VA and understand the cable must be buried 18" deep. I believe I can run it in the same trench as the sewer line and water supply line so long as it's encased in schedule 40 or better conduit but I'm not absolutely certain on this.

Any suggestions are appreciated! #Lighting&Electrical