You can start understanding 80-90% after reading this
https://www.pdfdrive.com/physics-d183889574.html
Just focus on projectile motion chapters 2-3-4 (projectile is 4) .
No excuses will be accepted that its too difficult to follow etc lol. It is very basic math and will make you proud to read it and see you understand it all. 1-2h per chapter.
Test your knowledge also here (i promise you if you read on your own these 2 resources you will feel so excited)
http://web.mit.edu/~yczeng/Public/WO...201%20FULL.pdf
An alternative also easy to read book is this
https://www.pdfdrive.com/physics-e184892107.html
Same first 2-3 chapters ( i think this has solutions too either in this book or another one on same website Giancoli solutions)
I suggest buying for real these books i link by the way to all here. They are a good thing to have in your library and easy to follow at all ages.
Make a plan to spend 30min per day or 2h per week at a particular day and after 1 month you will be very good in many things you didnt expect.