From my experience, finding a co-founder is not something to rush into by just interviewing people. A co-founder is someone who will become an important part of your life, so they need to be good at marketing, smart, and have integrity.
It’s not easy to find someone who fits all these criteria, but it’s worth it because you want to build something that lasts with someone you can count on.
Until you find such a person, you can hire someone to help you with marketing while also learning some marketing yourself. This way, you won’t be taken advantage of, and you’ll also expand your network of marketing professionals, increasing your chances of finding the right co-founder.
I think what you need is a creative person who can create appealing visuals. Finding a co-founder might not be the best idea here.
A co-founder shares equal responsibility and you might find it challenging to balance roles. Instead, hire someone as your first hire who can create content or look for a freelancer on Behance or Dribbble who can create great visuals.
Also, learn marketing and sales yourself. It’s not hard to get the basics at least.
You are right, there are lots of freelancers claiming 5-7 years of experience but the quality is just bad. Before hiring anyone, you should hire a hiring agent or manager to find the best talent available.
Also, before hiring anyone, you should have some knowledge about that area, otherwise you won’t be able to judge candidates.