I need help building a business portfolio

I want to build a portfolio for my business that I want to start I'm 30 yrs old with tons of experience in concrete, masnoary, carpentry, electrical, HVAC, interior remodeling along with exterior remodeling. I've been working the trade since I've been 15 yrs old and since then I've learned so much more, I'm ready to be able to work for myself and not another company.