Both concentration and motor skills are something that can be improved.
I have trouble concentrating if I do not have enough sleep, if I am stressed or depressed, or if I am not eating well. I’d advise you to make sure you’re getting enough sleep and eating well, eating a diverse, well-balanced diet. A lot of people do not eat enough Omega 3 (in fatty fish, walnuts, canola oil, and a few other foods), and that can improve mental function in a number of ways, and also have other benefits for health. Try to eat more whole, natural foods, and avoid processed foods and junk food.
Taking regular breaks, when possible, can also improve your concentration. It’s simply impossible for people to focus more than 2 hours or so at a time, and often you can’t even focus that long. But if you take a 10–15 minute break to really relax (not trying to focus when you’re having trouble) and then come back to it, you may find your focus improves. Find ways to be at your best during the times when you need to pay attention to someone’s directions.
As to holding and using tools, practice makes perfect. Motor skills are something you can get better at no matter what your age, and even if you are inherently clumsy or shaky. You may find exercises like qi gong or tai chi, or even some forms of dance, to help you to learn how to use your body more effectively too. This can also help with lifting / carrying things, and can prevent you from being injured.
Also, for concentration, you might want to try mild amounts of caffeine. Small amounts of caffeine, spaced throughout the day, can boost concentration, but large amounts at once can cause anxiety and jitters. For this reason I drink tea instead of coffee.
Good luck; I hope some of this advice helps!