How to display file only downloadable by a specific user based on username/student number?

I'm still a beginner with this so I hope you understand. I've been working to create a simple student portal for our college this pandemic times.

I will make a student portal so the students specially graduated students can see their own admin-uploaded softcopy documents, like good moral, grade slips/cards, and other certifications and soon they can see their grades. I completed the front end, register, login and out process, but I'm having a hard time to code in uploading the files/documents in the site.

1. What can I do to upload the files for a specific student number?
2. Can I match the student's number to the filename to be uploaded? E.G. Student Num.=123456789; filename: 123456789.pdf

More Example (Scenario):

Student No. 1234568789 wants to download the files, he/she will register first, then login, and in the homepage, directly (i will not create downloads page), the documents specifically for him/her will be displayed and be available to download.