Suggest you call SCORE for a free business consult. SCORE is a part of the SBA and has 13000 volunteer counselors available. Just go to SCORE | Counselors to America's Small Business | SCORE
where you can sign up.
In good times, a few banks would only loan to start-ups with a 5-year business plan that showed how the money could be repaid. And, then they required a borrower to have one-third of the cost of the start-up in hand. Now, I think it would be a real problem.
On the score website, they offer downloadable business planning forms.
Having personally counseled over 300 start-ups, 50K is just not enough especially when it comes from HELOC or credit-cards...the first thing a bank does is pull your credit score......
I think for 50k you could buy a van (used) get a rug cleaning setup and do that. However, you are going to suffer lack of customers till you get started.
Just a prediction, no one will loan you money!