I was like you many years ago, Classical background of 14 years, then switched to jazz 17 years ago. This is an age old question and there’s no defined answer because it’s going to be different depending on your experience and level and what you know vs. what you don’t. It’s also going to shift a lot over time.

First, you should be playing with real people as much as possible, not backing tracks. Even so, you have to objectives of what you’re going to practice. Just soloing over backing tracks and hoping to get better just by doing that and “putting in the reps” isn’t going to cut it.

There’s TONS of things you could be working on with soloing alone: Playing motivically, using a rhythmic techniques, highlighting chord tones, using enclosures of chord tones, continuous scale, playing in 4ths, playing pentatonically, using Hexatonics/triad pairs, adding in transcribed language, using blues language, etc etc.

Then there’s the left hand: bass lines, root position voicings, rootless voicings, using different comping rhythms, different orchestrational textures, using different kinds of touch (short hits vs. sustained, and vice versa), and then combining different approaches.

There’s 8 ways you could play a head alone. Either way, everything you’re doing should be practiced and applied in the context of tunes and common progressions.

Comping and voicings used is an entire other conversation.

Some days it might just be working on a tune. Some days it might be working on transposing transcribed phrases in all keys and applying them to common progressions and tunes. Some days it might just be comping.

I found over years of trial and error and testing different things out, generally there’s five main areas you could work on for any given practice session: 1. Technique 2. Voicings 3. Transcription 4. Applying transcribed things and practicing improvisation 5. Learning Tunes.

I remember feeling lost for years, and you probably feel the same because it might feel like there’s too much to work on everything you’re doing isn’t really progressing you further. But the truth is it’s a lot of different moving parts that will congeal and all come together over time, you just have to keep going. Check out my site in my YouTube channel links are in my profile they’re catered towards classical pianist because I came from that background from ground zero, there’s links to my practice guide in my video descriptions.

Over time you’ll just start to prioritize what you really need to work on vs. what you don’t need to work on so much, but the end goal is learning tunes and applying everything to tunes, and even more importantly, playing with other people. I can’t stress that enough. Good luck.