Having plan with a peak or two doesn't mean that you won't try your best in races at other times, or that you'll be slow. It means that you'll be extra ready for the races that are important to you.
Top-20 finish in what kind of race? It makes a difference. Also, which race? Dr W's right, identify your goals. Go over the calendar, find a couple races that have courses you like or your girlfriend's going to come out to watch, and then work backwards so you do the work to get yourself ready for that course on that day. BTW "raise FTP" is an objective, not a goal, and it's a poor one at that. How do you know if you're done? Is 1 watt enough? 10? 30? "Raise FTP 20 watts by august" is a better way to put it.
Also, don't listen to the Internet bravado here. Setting goals that are too hard to achieve are a waste of time. If you've never finished in the top 40 of your favorite event or finished it at all, then top-20 may be a good goal for you. Goals are supposed to be a reach but attainable if you are dilligent and put in the work that you have committed to.
Friel's Training Bible book is a good template for figuring out your goals and the objectives you need to achieve to reach them, and setting up framework of a training plan.