I saw this tutorial series in a post but I believe every beginner should watch this. Don't skip any videos and make sure you pay attention.

https://www.youtube.com/playlist?list=PL8hp7Ohapfw35BHsO0LO5FnCUtrpQDRiF

Worth watching the entire 120 videos, I promise.

Definitely worth watching. There is so much out there to learn, even if you have a good fundamental understanding of mixing there will always be techniques or tips that you can discover and test out in your mix.

Check out some of these other tutorials that offer really great advice and production techniques:

ADSR Courses https://www.youtube.com/channel/UCf5UKh_cj2_5pUomhyswWYQ
SeamlessR https://www.youtube.com/channel/UC2mgCVJWitRUTIpgd7pLung
The Pro Audio Files https://www.youtube.com/channel/UCVdU3CMnJ-edC4FeCXK4b3Q