Everett
Much depends on what your starting point has been? If you have been playing soccer at a high level for a while ( define how long?) then the adaptation to the work might not take long but you need to start somewhere but likely slowly especially if you are still in competition mode. While your questions are important you need to undestand their are a multitude of variables when integrating any type of work.
Ideally I would ask if you are currently doing tempo and if so how much and how often? Plan for a small amount now and design a proper progression come the end of your season depending on where you live.
I know one member on the site in particular and I let him know you have posted as he has been working with soccer players in your age range and had great success. Perhaps he will be able to get into some specifics with you.
Rest intervals will alter with fitness. Some ways to think of tempo with regards to rest. Initially you want to get the tempo done and keep the breaks challanging and consistent with the rule of thumb that you must finish the way you end. Historically I always make a distance ( 10 x 100 rest between sets was always 25 meters walk basically running goal post to goal post on most fields for football ( yes canadian football fields are different distances than US football) and then walk out roughly 12 meters / return and run back. / as fitness improves over time so does the speed of the tempo maybe and sometimes but it need not depending on what is getting done on the other days? / speed? / intense soccer skill? / what matters is the tempo does not take too much out of you for the primary focus of your training /
Just a start to some info so let us see what you come back to us with.