If you're 18, your hormones are prefect for adding muscle or getting lean. Take advantage of that by increasing calories to gain, and a modest cut to calories when you cut with added cardio. Target a 500cal deficit when you cut.
Google base metabolic rate, and calculate what your base rate is. Add in exercise and you've got your daily maintenance calories.
I'd cut down to 1 shake during the day (post workout). You can add oats to your shake, ~1 cup. It's best to grind them in a blender or magic bullet first. Oats make me grow like nothing else, but are great on a cut too!
Also, for breakfast eat 3 whole eggs and 3-4 whites. It's 6g protein for whole eggs, and 4g protein for whites. Try to get at bare minimum 20g protein from the eggs, preferably more. Buy eggs in bulk, they're awesome for gaining and cutting (less yolks in a cut, like 10 whites and 1 yolk). Hot sauce goes great with this, something like Frank's or Cholula.
Cardio, I'd start off with 20 minutes, two times a day. Once in the AM, once in the PM immediately after you're done lifting (save the shake for after cardio, the time delay is actually good). If weight isn't coming off the way you want, increase the time or frequency on cardio.
Supplements, really don't NEED anything if diet and exercise are done right. CLA never did anything for me, and I went through >1000 pills over a period of time. You do want to include fish oil though, and a multivitamin, and some protein. If you want to get exotic, you can get a fat burner like Forged Burner or Adderlin from
www.needtobuildmuscle.com (coupon code "needto139" gets you 15% off), with free shipping. Another option is a nutrient partitioner like Need2Slin which you can get from the same place (basically an insulin mimetic that helps shuttle food to the muscles rather than fat). Also a BCAA product would be good, something like Xtend (helps preserve muscle in a caloric deficit). Those last few are optional, and depend on how much you want to spend.
If you've got any questions, just let me know.
