window installation company

Greetings!

I am new to this forum and realize that window installation is not exactly why people are here however, if there are any window installation companies/contractors on this forum, I'd love to hear from you! 

Here is the thing. I run a glass cleaning company in the Bay Area and have always wanted to add window replacement to the products/services we offer.

My question is, should I get my contractors license first? 

Thank you.

Patrick