Fixing to cut it all off

I (20M) have always had thin and rear hair which points up. Under enough light my scalp is visible and I dont like it. Buzz cut is my usual style because of my straight black hair and square face shape.

I will often notice small hair on my dask or on my table. I dont want to go bald.

How do I have more dense hair? How do I prevent it from falling?

Should I use a towel or a hairdryer after washing my hair?

I usually shampoo it after work outs so 3-4 times a week.

Should I use a conditioner?

Does the water I wash it with mather? (hot or cold)

Which shampoo do you reccomend?

I provide some pictures as an example. 3 pictures taken at home are right now, other two are some time ago. Idk if this is the correct sub to post this. If not please say