From what I have been told by Knowledgeable people who are involved with college coaches, and have multiple players committed or in college already, the summer completing 10th grade is the time to go. But, pick your schools and go to their prospect days. There are only a handful of Prospect days that have a good showing by D1 schools, and they are usually invitation only. I would check out the Blue Chip225 as a good learning opportunity, and a way to get some experience at a competitive level. My son did it and worked with great coaches, but not a ton of D1 exposure.
I was told to spend my money on training this summer, and to make sure that the team you are on is going to good tournaments. Nobody is looking at 2021, 2022 or 2023 this year with the rule changes, but next year, everyone will have their eyes on the 2021's, so get ready for that year, unless the rules change again.