Where to start as an independent travel agent.

Sorry if my question sounds too basic. But I want to make sure I am on the right track. I am tired of corporate world and want to work for myself. I know it is challenging to promote for myself and find customers. So what I have been trying to do so far is:

Since I am based in ON. Canada I need to get my manager Tico certificate.

Set up my business account with booking and expedia.

I am sure I will need my sabre cert. anything else?

For corporate world we work with vendors who do all the bookings. How is it done exactly for an independent TA? through Expedia and booking?

I just want to do short trips for Europe and East Asia for now, so no all inclusive or cruises.