Gotta have a say on this, as it reminds me of me starting out on my "get fit" quest 3 years or so ago.
The responses you have seen here that you are presently dominated by slow-twitch fibers are correct. Why that might be is a different question, but it's an important one if you're developing a training program.
How have you worked out in the past? Endurance exercise, for example, will create a slow-twitch dominance (i.e. running, rowing, cycling at constant speed for extended periods (30+ minutes several times each week)).
Frankly, that's not as important as what you want to be, so what are your goals?
There's a moderately strong likelihood that whatever your goals are, lifting pretty heavy weights (75-95% RM or so) 2-3 times per week, then rinsing and repeating every week will (re)program your slow-/fast-twitch ratios, and make healthy compositional changes (improvements?) to your body.
Assuming your goals are to become leaner (and maybe even larger - but not fatter) then following any one of the myriad of training programs on here will yield excellent results - possibly in short order. The speed of improvement will be related to your past: if you've lifted heavy weights all your life, then the improvements will probably come slowly.
If, however, you've either been a slug all your life, or if you've only done low intensity cardio then you will probably respond dramatically to a program that involves strength-training and/or high-intensity cardio.
However, if your goal is to run a marathon or six, then you will still have to keep the endurance cardio stuff going - and for the gruelling long sessions, too. This will virtually, if not exactly, mitigate the effects of a strength-training program, making it arguable as to whether you should even bother (some say everyone benefits from strength-training. I personally agree with that).
So, as you can see, it really comes down to your medium term goals - can you share these?