step one is probably to get your hair to a more healthy state, it looks kind of flat and dead as opposed to full and healthy.
try either completely removing shampoo and conditioner or using them on a less frequent basis, such as once or twice a week. If you choose to use them, make sure to get on free from sulfates, dyes, artificial fragrance, etc. You can get an ingredient analysis for free on EWG skin deep (google it).
if your hair is thinning, use a derma roller in combination with rosemary oil/rice extract
step two is styling it. once you have healthy thick hair, experiment to see what suits you the best. some people look good with a middle part, some people cannot pull it off. Likewise, some look good with a crew cut but again, others may not. It comes down to your face shape, take a quiz online to find out what you should try.
to get a thick look to your hair you have many options of products, including leave in conditioner, mousse, pomade, wax, styling clay, texture powder, etc.
it can all be overwhelming but look at the hair maxxing thread in must reads, and google has all the info you need