What do you do when there is no one left to spar?

You should compete more. You're not getting 1st place everytime you compete, so there is obviously room for improvement. There are also other things you probably need to work on, like forms, one-steps, and jujitsus/locks/takedowns and self-defense technques. How are you at fighting multiple opponents?

And, maybe you should consider coaching the junior students to fight as well as you do, seeing as someone took the time to get you to where you are. Could be time to pass the torch and share the knowledge.

Try to go over what went through in class. Do techniques and evaluate the technical aspects to perfect them. Study for any small glitches and mistakes, needing little tweaks to correct them.

have u checked out your local bar

theres always a few retired practitioners goofing around

pick on one and see if hes up for the task

and remember to take it outside

There will always be people to sparr sparr the same people in a row . That s what I would do when I did tae kwon do sparr lots of row sparring .

Go to a Muay Thai or Kickboxing school (or even better, MMA) and go spar with them for a bit.

training can do anywhere and althought any patner, but if you still learning basic you need it, try find another dojo