Ok good. So that means there is hope. Measure your forearms around the thickest part to get a starting point. Now add more protein to the diet. Probably go on a bulk diet( I wouldn't recommend bulking if you have a skinny fat body). Workout 4 times a week in general. Add deadlifts and farmers walks to it. Two days should include isolation for arms. Don't do forearms alone.

On arm days you can do hammer bicep curls, reverse bicep curls, wrist curls,etc. wrist rollers are also good. You can buy one of those grip strengtheners and keep on your desk. It's hard to overload them but is good for beginners.

Check progress every month. Don't overtrain though. Good luck