Looking for advice: How did you get started in mini-storage?

Looking for advice on getting started in self-storage. I posted this in r/passive_income but didn’t get any advice. Hoping some folks here can help out! Scroll to the bottom for a TLDR

Hey guys, new here and looking for advice from people that do/have done mini storage.

I’m in my early-mid 30’s, single, no kids, make a pretty strong salary. I’ve backed my hours off recently,to be able to travel and relax a little more, so I would say a safe range for incoming cash from my job is ~ 20-25k net/month.

When I was in my early 20’s going to GCU I bought a home and a 4plex in the Phoenix area using VA loans. They were really cheap at the time and now, both are paid for now and probably have about 750-800k equity combined. Monthly combined rents received ~$4200-5500 depending on vacancy.

I have an opportunity to move to NC, and it will probably take my monthly net up to 30-32k/month. I’m thinking if I move cross country, I’d probably sell the properties in PHX.

I was in school/residency for about a decade, and just started making this kind of money recently. But I have just recently really started thinking about how to make my money work for me. I’ve maxed out my Roth retirement account options each of the last 3 years. I just drop everything above my living expenses into a managed index fund with JP Morgan right now (averaging contributions of about 12-17k/month.)

I’ve got about 200k in non-retirement liquid accounts (high-yield savings accounts through AE)

I own an old(2012) Chevy 1500, that I’ll need to upgrade soon, and I have rented for the last 7 years because I did school and residency in SoCal, and didn’t want to mess with owning real estate/being a landlord there. Worked through undergrad and used GI Bill for grad school - so fortunately I don’t have any student loans. If I move to NC I’ll probably buy a home, ideally between 500-750k.

Okay all that background just to ask this question: what is the best way for me to get started in mini storage? I feel like it is the best way to make passive income, and if you have an onsite manager, I assume it would be pretty low stress.

I could be totally wrong and I am open to any and all feedback! Thanks in advance!

TLDR; want to get started in mini-storage as a way to earn passive income. Make about 250k net/yr now, and will likely go up to about 360k net/yr next year. Roughly a million dollars in liquid/semi-liquid capital to get the ball rolling.