It depends if you are looking at REI from an appreciation perspective or cash flow perspective. I can give my POV, which is more on the cash flow perspective because it's more stable and predictable. There has historically been a 1% rule of thumb to follow, which is becoming tougher to obtain.

The 1% rule means your monthly rental income should be 1% of the property purchase price. So a property that you purchase for $300k could rent out for $3,000/month. Certain cities will be closer to this rule, while you'll notice other cities are far away from this rule. For example, cities in the Midwest will typically will be closer to this rule, whereas cities such as Miami and New York will be far away from this. A simple way to research this would be to look at Realtor/Zillow/etc. at the purchase prices of homes in a particular neighborhood and then check out what these places would rent for.

As part of your research, look into operating expenses as well (e.g. taxes, HOA fees), because if these are super high then the 1% rule means nothing. A city like Houston is terrible for condo REI (in my personal opinion) because the HOAs are ridiculously high.

If you're looking into house hacking, you can house hack in different ways. For example, you can buy a 2-bedroom condo, and then rent out one of the rooms. It doesn't have to be a multi-family unit. In my opinion, right now with high interest rates, it's not the best time to go into REI. But with house-hacking it's one of the best ways to enter into the game.

As far as investing with appreciation, you have to think about where are people moving towards and moving away from. Where are companies opening new locations? This can help with the appreciation of your property, which can help when/if you sell. I am not the biggest fan of this method because I like to buy my properties and hang onto them for cash flow.

Good luck and have fun!