Don’t take loans to pay yourself in the early stages. Like the reply above says, speak to your dad but in the meantime seek a more flexible job if possible.

Sounds like a good opportunity. There’s loads of good comments on this thread that are hopefully allowing you to see numerous different angles. I would add to this that it sounds to me like the person offering you in wants to get rid of the day to day running of the business and therefore invest their time elsewhere. Likely is that they see a future with you in the business. I’d want to understand clarity of roles in that. You don’t want them hawking over you saying “I wouldn’t do that” all the time but at the same time need to learn from their experience. If they’ve been doing it 15 years, then they know what hard work is. You should know that running a business is nothing like working in a business. I personally like the idea of partnerships but I have had, and dissolved, a couple because I felt like the other party wasn’t pulling their weight. Good luck.

I’m big on just doing something and being around the right people. I started as a freelance project manager in marketing. Worked in a co-working space around a Tech Community. Now building a startup community business. I still run projects, as the core service grows, that keeps cashflow in the business but eventually we will flip. I notice that a lot of the successful software companies I work with employ a similar model. At heart, they are building products, but their teams still offer contract dev work to keep cashflow while they build. This also has the added benefit of meaning they can bootstrap rather than raise to fund growth.