Not sure I am reading your "take Advantage" comment correctly, so I answered A/B options.
A. Don't use your parent's house equity for your REI. Don't learn on your parent's dime.
B. Yes, it sounds like a great project with your parent's house, but you can help them do it for them. 1. Do they have enough income to support paying off a project loan?, 2. Take out a home equity loan and they do the rehab.
If this is for You. To get the most out of your post, put down your information.
Example: If your 25, only have $3,000. I would recommend you apartment rent or house rent hack. Do what fits your financial, experience and risk level.
1. They dont have enough income to support paying off a project loan. Theyre on social security.
2. My original plan was to take out a HELOC on my property to renovate theirs, but i need a way to pay myself back. Which is why im trying to use their equity to pay myself back.