Hi Hasan.
Welcome. Let’s see if we can get you started.
You don’t have to read it all to start. 🙂
Checkout the Advice for New Contributors, and then see if you can get set-up with the Unit Tests.
Both of those link to a tutorial on writing patches, that’s worth stepping through.
More or less, if you can get the test env setup and run the tests then you should be good to go.
Then there’s finding a ticket.
Here’s a link to the issue tracker, showing the open tickets for contrib.staticfiles.
You can adjust the “Component” drop down and hit “Update” to see other area, and add/remove other filters at will.
We have ≈1100 open accepted tickets, so you should be able to find something. 🙂
If you get stuck, or have questions, or anything else, do post back here, or on the Forum, where there’s a “Mentoring” channel.
Hopefully that should get you going.
Kind regards, Carlton