Just look at your life and the path that lies behind you.
For me, I've been running my own design company for 15 years until I realized I am – due to the experience I made – perfectly able to solve scaling / capacity problems for other creative agencies, too.
My 2 cents about outsourcing: Either go low- or no-code and build it yourself or hire someone decent. Fiver, upwork, etc. are full of talented and respectable freelancers – but you will need time and money to find them in a haystack full of "experts". As someone with a lot of experience in managing people and projects, I tell you this is not an easy task. No less, if we're talking about your own money.
My advice is to go low- or no-code, keep the expenses low and release a MVP. Then go from there. If you app monetizes, invest the money in a more polished code base, etc. You get the point.
Good luck, go out there and rock!
Manual of the Warrior of Light (Paulo Coelho). It sounds cheesy, but things stick.