New and need help!

Hi im new to this site and need some advice! I have no idea how to diet..like whats good to eat, how much etc..? I have cut out all my sodas almost completley already and am drinking water alot more than I used to.. This is a given so I new to do that :D Im about to be 22 yrs old im 5 ft 3 in and weigh well im going to say 162. (Thats what the Dr office said) Well I would ideally like to be around 130-140. Closer to 130 my Dr said 140 would be ok. I work night shift so im trying to get out of the habit of snacking at work! Sometimes its hard to cook so as a family we have been eating out alot more than usual since I started work in March. Can anyone give me words of encouragment! Tell me what you eat and how you exercise! Thanks in advance!! :)