HELOC use help! What is the best use?

[Marc Young]

I need some help on what to do with using a HELOC. I am selling my 1st rental property and made over 300k on the house. We have decided to buy a bigger house in the same neighborhood I live in now, put 200k down on that. My dad offered me to assume(loan company said I can) his loan on his rental property that he does not want to landlord anymore. I'm going to give him 100k on the side. With me assuming the loan it is cash flowing $900 per month. That house will have 150k equity. Then the house I'm moving out of now I will rent out. Renting for my mortgage $$

Here's the question. I plan on taking a HELOC on the new house I put 200k down on and the house I got from my dad. So how would I deploy that money to scale my portfolio to 5,10,15 properties?

a few ideas. 1. Use it for a BRRR. I've never done one.

2. Use to put the $ down to buy another long term rental. Just the cash flowing to pay back the HELOC. (Worried $ will be tied up to long)

What's the best use of this?!