Any tips for Drill school?

Be humble, keep an open mind. You’ll soon realize that 90% of what you do right now, is not how things are actually done. Have good uniforms. There is no such thing as a field uniform. Be prepared to learn and embrace the next two years of your life!!!

https://www.presby.edu/doc/military/FM22-5.pdf

This is your new friend. Read it and memorize it. Word for word, from cover to cover. Oh yeah, don't be that guy who failed the PT Test.

Believe it or not, I spent some time practicing my modules & command voice :
1- In front of a mirror
2-Letting someone watch me modulating & following my module script. It worked for me writing it down first after memorizing.
3- Standing by a tree "trunk" at attention modulating. It looked crazy, but it calmed my nerves down.

Good luck.

Be in shape, make sure your head is clear of anything that can interfere with your practice or studies, and don't take things personal! You will be ok!

Please review these threads, which cover this topic in multiple ways.

https://www.rallypoint.com/professional-military-education/drill-sergeant-school

Learn and "KNOW" the 5-Step process PICCA, and the terminology, nomenclature, and types of commands in FM 3-21.5.
If you know the terminology and nomenclature, it makes it easier to describe the movements without having to recall those things while under pressure. Learning these will pay off.
When testing, if possible, pick a demonstrator that know what the h$!! they're doing AND pays attention-to-detail, and look at your demonstrator. You want a demonstrator who will perform the movement as you describe it, NOT as it is supposed to be done. For example, if you're testing on rifle rest positions and fail to say, keep the toe of the butt of the rifle on the marching surface, your demonstrator will hold the entire butt of the rifle on the marching surface (or off). Take a last look at your demonstrator before using a consistent sequence (i.e., feet, waist, arms/hands/fingers, chest, head).
Be comfortable making, and correcting, errors. Don't fall apart if you state something incorrectly; direct your demonstrator to reform, then state it correctly as if you did nothing wrong.
Everyone studies differently, but here was my method. I ate dinner, then took a nap or quiet time of at least one hour after the end of the duty day. Your mind needs a break before it can efficiently learn again. Personally, I napped a couple of hours, would study a couple of hours, check the training schedule, and lay everything out for the next day. I noticed that the students who began studying immediately after class, would still be studying when I awoke from my nap, and would still be studying when I went to bed. Those were the folks who ended up getting falling behind.

Be sure you're in top physical shape because you're going to need to be!!!