I appreciate your gung-ho nature and willing to get started. That being said, you might be trying to do too much too fast with too many life variables in front of you the next 12-24 months. Doesn't make buying/investing/managing impossible, but certainly much tougher, just slow down and get all your ducks in a row. Unless you have rock solid boots on the ground (your team - realtor, lender, prop manager, contractors, local family) in the places you want to buy, I would be very careful to do anything quickly.
Unless you're looking at a suburb, $200k for a "decent sized SFH" sounds a bit low. I live in the military town you may be stationed in, and have been eyeing Dallas and Austin, and most quality SFH in the heart of the major metro areas are not that cheap. Who would inspect it for you? Do any work? Manage it monthly? @Jaysen Medhurst lays it out pretty well, he made some great points about DFW and SD. I would be real leery to trust family with my investments, unless they are well established professionals in this space already. "Cousin Ricky" ain't touching my stuff ...
Have you spoken with a lender in TX? most NOO (non owner occ) rentals require 25-30% down, then you will need closing costs, capex/maintenance reserves, plus any costs to upgrade the place and get it listed and carry all the costs till a full time renter is in there (could be tough with COVID). You may need more cash no matter what you do for OOS investing.
$500k in San Diego doesn't buy you much, depends on where you want to live and what type of property. Donald A. has posted some new builds around Oceanside recently for around that price (you are one of many SD type new buyer threads recently, do a search), and that is very close to Pendleton, but that is very north of town and not near PB or Gaslamp or Mission Valley or really anywhere. Depends on what sort of lifestyle you want in SD. Most Navy kids want to rage the beach and party at Fluxx and living in O'side would make that pretty tough to do without 30-45 minute Ubers each way every night. $500k for a SFH would be nearly impossible unless you went north or east, and those are not really "San Diego" and where young military single dudes want to live IMO. We need to know more about you to understand your limitations of where you'd want to live, assuming you even know a thing about SD.
MF in SD will be $1M+ nearly anywhere unless Twana has links to otherwise. The last "decent" (not a s___-hole) 4plex I saw in North Park was $1.6M. The only way it made sense to buy that (from a cashflow perspective) is to 1031 exchange a crap ton of equity into it, so the payment is decent. Otherwise at surface level you would lose your pants renting out at that acquisition cost. Thus you see very competitive buying in MF because they are havens for 1031 exchangers.
My thoughts
1. do whatever you want, that you feel comfortable doing. it's your life, your money, just do your homework. A lot of it.
2. I would wait if I were you, two reasons
a. too much uncertainty with your military career and moving around, that makes managing property tough unless you go full turnkey
b. COVID is going to drop prices in many places, waiting should net you a better deal. It will take time for RE to really feel the pain of evictions, non-pay, foreclosures, job loss, etc. It is a trailing result, where stocks drop by the minute, RE takes time to sort out because no one moves quickly in that industry. The longer you can wait, the better a deal should be out there. If you are in your 20s, sure you want to get started, but these are expensive decisions, don't make them too quickly.