Adjusting brakes

You did not give us any really specific description of the problem. Therefore, any tutorial for adjusting V brakes should apply. If it is grabbing on one side, you adjust those small screws at the pivot. One of them is visible in your photograph. Using those you make the calipers to be centered around your rim. Then you just adjust the cable pull using your barrel adjuster (at your brake lever) or even at the cable clamp (at the top of the right caliper).

Those should be the important points for you. Full tutorials and descriptions are widely available.

You have V-Brakes. These take some setting up but should work okay.

Steps:

1. Check your wheel rims are true. If there's a buckle or sideways-wobble in the rim, then the brake pads have to be further apart, so true the wheel with a spoke key.
2. Check the brake lever is operating smoothly, with enough "yoink" in the spring to return to the open position. If not, clean and lubricate.
3. Check the inner cable moves freely - this system depends on the two springs in the brake arms to retract the inner cable, and if there's friction stopping the cable from running free, then the brakes stay "on" a bit. If the cable runs poorly, you need to replace the inner and outer cable.

Once all that is done and working, then you can do your brake arm adjustments.

1. Make sure the brake pads press against the rim, and not the tyre and not under the rim. Easier way to do this is unclip the cable at the top, work on one side at a time, back off the pad's nut, press the pad into the rim via pushing on the end of the brake arm, and then snug up the brake pad's nut. Repeat on the other side.
2. Reattach the cable at the top. Check that the pads ride clear of the wheel rim, but not too far away. Less is best, without any rubbing. If the pads are too far apart then try fiddling the barrel adjuster up at the lever, but if that's not enough; tighten barrel adjuster, back off the pinch bolt holding the inner cable, and pull a few mm through then clamp down again.
3. Balance the brake arms. Each has their own spring to pull the pad off the rim. You need to tweak the spring force to be even, by turning the tiny screw under the brake boss on the frame. It could be a ~2mm allen key or a small philips or flathead screw. One turn inward would increase the "pullback force" of that spring.

It can be a bit fiddly, but with patience you can make your brakes better. Perhaps not perfect - sometimes the pads themselves harden with age and need replacing.

Pads do wear down over time. If yours are worn past the printed "wear line" then replace.

The springs can also loose their tension with age too - there are usually 3 different mounting hole options, if you remove the whole brake arm. 2.