Thats why ive adked for help because i am a beginner . The brakes are not working well and i need to tighten them but these disc brakes ive not tightened before
You don't need to tighten them. That is not a thing with disc brakes, certainly not with hydraulic. They are self-adjusting until the point where the pads are worn out.
Whatever the issue with the brakes, that is not it.
If the bike is quite new, then the most likely issue would be air in the hydraulic lines, or contamination of the pads/rotors. If they feel spongy, the former is more likely. If they feel firm but just don't work, or squeal badly even in the dry, then the latter is more likely.
If the bike is older, then worn pads is also a likely reason for them not working well.
If the issue is that the pull is too long before they bite, then that bike has Clark Clout brakes, and there should be an adjustment screw to adjust the reach, found on the inside of the lever.