How can i improve my concentration?

Do only one thing at a time. If thoughts race to other things to do, then keep a paper nearby and write it down that you'll do it later, now just focus on the task at hand.
For me, listening to music in headphones on a low volume helps me concentrate more while studying or doing anything.

Try them mind games to keep your brain sharp or join a concentration camp

Try doing one task at a time. Start slowly, when you're getting used to it, go faster.

Make a check list and focus on one task at a time

meditation and yoga

i've been trying for 34 years bro. idk.