I have a lot of trouble concentrating in class

You can use fidgets at your desk just maybe not ones with sound because it can be a distraction

I have the same issue, and I do a few things with various success. 1. If your class gives the slides online, best to look over them before class. And during class, just write whatever they explain or note about, making a point to just write what slide they are talking about. You can just look back later on the actual slides and if you have time, add the extra stuff. EX: [On the 4th slide: Mitochondria is the powerhouse of the cell… in your notes: 4. Mitochondria = energy (ATP)] 2. If a friend would agree to it. Make your notes as if you are going to give it to them, like they are in the class and that day they’ll be absent. It kinda forces me to concentrate more as the person would later use this for their own work and I can’t just give them nothing. (You can ask them for reminders about it or actually send it to them to make your brain think they actually need it.) 3. As mentioned by others, doodling. Though I say try to doodle things according to what is being presented. You can make them as derpy as possible as long as you get something. While not the best, it does give some creativity and makes the presentation more involved as you have to make doodles about it. 4. Try to rephrase it in a derpy/ funny/ interesting way. Making it more memorable makes it more interesting and easier to remember while also making you think about how to write it.

Try drawing while listening or coloring, it helps many (me too)

Maybe fidget toys, they help me a bit (I have trouble concentrating too but mostly because I am gifted and therefore bored af in class so I don’t know if that helps)