Welcome to the boards nadia! First - lots of good info - use the search feature often! Also read the stickies on the top of this board for some basic info and answers to common questions.
First, you want to lose bodyfat "as quickly as possible" -- there are no miracle pills. Some may say DNP, but you are a self-admitted newbie - DO NOT MESS WITH DNP! If you don't understand the basics of diet & training, you will only hurt yourself with the high-power stuff.
Being 5' 10", 145, I can't imagine you have a unreasonable bodyfat level. Get it tested and find out so you have a real number. Some may say the number isn't accurate, depending on method, etc. - but when you are starting you really just need the base number. If you continue to get your bodyfat tested as you train, maybe once every month or every couple months, you can see your relative improvements.
You say you don't want to get bulky and you only do light weights. Don't worry -- unless you are lifting very heavy with a trainer several hours/week or using AS you don't have to worry about getting bulky. Sounds like you need a reasonable training program - and don't be afraid to lift some weights - you'd be amazed what your muscles can do. Flapping around doing hundreds of reps with really light weights is mostly just a waste of time. Yes, do some cardio - maybe 3-4 sessions/week - best is on an empty stomach in the morning for an hour. Doesn't have to be at a screaming pace -basically get your heartrate up and perform at the point where its hard to talk and do your cardio at the same time.
Losing bodyfat is basically a function of how efficiently your body can process the calories you put in. 5-6 small meals every 2-3 hours, with good quality protein, clean complex carb sources like brown rice and sweet potatoes along with lots of dark green leafy vegies, and some good fat sources, e.g. 1 tbls flax seed oil or natural peanut butter or soy nut butter. Use good quality protein mixes to help supplement your protein intake. Use protein bars in emergencies (e.g. driving home, stuck in traffic and coming up on one of your meal times) - Pure Protein bars are good -- low carb, low fat. LOTS of water -- like 1-2 gallons per day.
Recovery is just as important as training & diet. Make sure you are getting a good night's sleep. Use l-glutamine after your workouts to help support recovery.
ECA -- thermogenics like Ripped Fuel or Adipokinetix are good. They are over-the-counter. Don't mess with clen or T3 or lipokinetix (has been taken off the market anyway) or the other non-OTC stuff. Remember that these are ephedrine sources-- you don't want to abuse these. Also remember that if you take them too late in the day (after 3 PM) you will probably have a hard time sleeping. If you drink coffee or diet Coke, add this to any thermos you are taking and you will really get jittery. Try one or two of the OTC brands of ECA and see which you feel best with. Some people get headaches or upset stomachs or just can't handle the buzz from certain brands.
Things like winstrol are NOT thermogenics or fat loss supplements. These are hormones and are intended for muscle development. Some may get you more cut, but you are 19 and not looking to bulk so this is not anything that you should be interested in right now.
Start with cleaning up your diet, makign sure you are getting enough protein and clean carbs and fats, hit the weights with intensity and throw in the cardio. Don't expect overnight results. It generally takes about 3 weeks to establish a 'habit". You may notice some initial weight loss, primarily due to water weight -- NOTE -- not from drinking lots of water, but from the diet change.
It sounds more like you may want to tighten up / tone more than really have extra fat at the weight you mention, so do the above for 6-8 weeks & see how it goes. After that change up your lifting routine a little and adjust as you go.
You will obviously have to spend some more time getting some more details such as a specific diet or training split - spend time researching and asking questions on this board and I also recommend the diet & training boards as well.
Good luck!
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): I'm 19, 5'10" and 145. I want to reduce my body fat percentage (it's high) and gain muscle mass for a modeling shoot soon...I have Hashimoto's (hypothyroid.). From what I'm reading, there are so many fat burners: clen/cytomel cycles, adipokinetix, lipokinetix, ketofen, winstrol, lean body, yohimbine, PPA, Md6, Fina, DNP...there seem to be so many options!! Because I'm not looking to get bulky, I do light weights and cardio, and just want to reduce bodyfat as quickly as possible, w/ supplements. Any info regarding what works and what's reasonably safe would be much appreciated...I'm a newbie! Thank you so much...
Whatever the mind can conceive, the hands can achieve 
