For example, I am managing his investment right now all for free, I let him to borrow my car and store all his tools in my home, so our relationship is very close.

Now, if real estate is something you do want to do, that's a different store.

I bought the property in 2022 believing that it was properly zoned for a restaurant on the first floor and a single unit above.

(I recently bought a quad and found out that two tenants did not have security deposits on file) Good Luck!

In 2023 we bought our first single family fixer upper, we bought it cheap with cash in an area about 2 hours from our current home.

Let's say I bought one home a year for the next 15 years.

All my current portfolio was bought and is managed remotely. 

I just won my first tax sale property and if all goes well (AKA the judge reviews the property and approves everything) I will likely go down the tax sale rabbithole as the property I bought was pennies on the dollar (hopefully noone broke in and stole the copper plumbing lol)

The first 11 properties that I bought were all 100% financed, in one way or another, because I didn't any money.

@Moshe Cohen   The easy answer is called "delayed financing" assuming you are buying/bought the property with cash.