Making progress genius nice work 😁 😁  

I'm 20 and this'll be my 1st buy and hold so don't want to make any rookie mistakes.

One thing I highly recommend (whether they're voucher tenants or not) is to make a visit to their current residence part of your screening process.

But you are not building any equity renting your current place.Just keep a few things in mind: make sure the rental market can support your income goals, be prepared for the time needed to manage multiple rentals while working full-time, and stay aware of any lease terms that could affect your plans.

Usually HELOCs are used for short term purposes, so it would make more sense on strategies like flips.

All the points you are making support my assumptions. 

I want to make sure that I'm not breaking any law that would result us in a bad situation down the road. 

Basically, this will make it difficult to get an STR permit if you are no5 already operating the unit as an STR.  

Make sure they make a steady income and are not job hopping.

For this to be possible at your age, you are able to have a parent co-sign and use their credit, income statements, etc.