Bonjour
my oldest brother is very tall, interesting, ang good at drawning.
Mon frère aîné est très grand, intéressant et bon dessinateur.
OR
Mon frère aîné est très grand, intéressant et est doué pour le dessin.
My dad is good at work
Mon père est bon au travail = mot à mot, but not really correct in French
Mon père est doué dans son travail.= much better
there's no direct translation for "good at" ==>
est bon à..
est doué pour
est doué dans..
it depends what you're talking about
good at drawning = is a good illustrator, cartoonist .. there's no translation for dessinateur as a general word
est un bon dessinateur = is good at drawning
est doué pour le dessin = is good at drawning
good at his work = depends which work he is doing
hope this helps ☺