The easiest way to do everything on one is to use a PMS.
The free way to do it (and not overly complicated) is to build an online calendar (google tends to be the top pick) and then connect that to all of your accounts as the reference for availability. Almost all of the platforms will have this option, but it will be easier on some sites than it is on others. You may find that you need to update this calendar manually often to ensure it's up to date and you're avoiding double booking (again, a PMS automates this process and my others for you..but there are costs associated).
You may want to start branching out in a relatively measured way. Add VRBO and Booking.com, see how that works and then start adding more.
We ran 3 properties on Airbnb and VRBO with the "calendar method" for about 3 years, and it worked well. We've grown quite a bit, and now use a PMS (Hostfully), and we love it, but the lessons learned in those first 3 years have been greatly beneficial.