There is a lot of serious (and very, very good) advice in this thread. My advice is a little bit different.
You'll take for granted going through the ratings and the motions. You'll take for granted the little moments of "I did it". Slow down, relax and enjoy where you're at... enjoy your current pilot privileges... enjoy flying... Don't get so much tunnel vision on the future of your career that you forget to enjoy what you have right now. The little milestones are just as important as the big ones. Celebrate that first solo and your private pilot checkride. Take your first passenger up the day after you legally can and enjoy that part of flight training. It's a heck of a ride, don't lose sight that it should be FUN too. I feel bad when someone comes to me and says their "timebuilding" days were filled with structured flights to one of the 5 airports ATP let them to go. Where is the fun in that? And what are you learning?
I remember very few milestones because there are so many.. the day I solo'd, the day I got my private (June 6th, 2012) and honestly that's about it. But what I remember most are the adventures I had, the trips I took and the people I met. Don't take those things for granted because you're too busy building time for the next great thing.