Welcome to the site. You'll find a lot of help here from people who have already been through this, some several times.
We're in the middle of the process for the first time with our 2017 son. In his case, I don't know that travel ball is a must, but the kid has to play in settings where coaches will be there to see him. For us that means targeting a few showcases and, if interest is demonstrated, some specific college camps. I suspect if my son had a chance, or the will, to join a good travel team, that might take the place of some of the showcases and camps (but not all). Just our plan; there's a lot of options.