Dumbell for 106kg person??

you should just do lots of compound exercises if you want to build muscle, and loosing fat is pretty much down to diet.
Id suggest you should start with doing lots of bodyweight exercises like squats, lunges, press-ups, dips, pullups (if you can do them). and then getting adjustable dumbbells, or a barbell, in order to do overhead presses, bent over rows, and to add weight to squats and lunges after a while . Do a full body workout several times a week with compound exercises and your arms will grow just from the sheer amount of growth hormone released into your circulation.

Losing fat wise, just cut sugar out your diet and lower your carbs a bit, or a lot depending on what's your norm, combined with intense exercise, and you will get lean and muscled in no time (aka, a few months)

well getting adjustable dumbbells, or a set with different weighted dumbbells is useful as it allows for doing different exercises as well as eventual progress. 10kg for bicep curls is probably a good place to start. But as long as you are doing press-ups and sit-ups, i would suggest adding squats and/or lunges into that as leg exercises produce the greatest amount of growth hormone release, which is one of the most important factors in muscle growth and fat burning. If you get the dumbbells then those would be good to add weight to these exercises.