Even if you're not very experienced yourself yet, you and others around your level can help each other and put together a remarkably effective practice.
Tennis examples of basic building blocks:
Learn (and/or practice) how to feed balls (speed, spin, bounce, height, distance, rhythm, etc)
Drop balls for other person to hit
Collect balls to save time
Exchange observations, questions, thoughts
Provide feedback, knowing that you might not know much yourself yet
Film and compare, e.g. to online videos or your own previous recordings
Give impulse to try something else, e.g. when stuck
Gauge "performance" vs progression scales - where are we and do we need to make things harder or easier?
In other words, design your own "lesson".
For me, one breakthrough would be seeing more beginners on court with a basket full of balls (rather than a can), and together trying to figure out to figure something out :)
P.S.: With these kinds of learnings, you can then approach a pro and ask very good questions. Of course mostly geared toward how to organize your next - self-sufficient - session...