The most important thing when it comes to fitness of any kind is consistency, especially if you are starting out with little to no experience.

The first time I set foot in a gym outside of college, was nerve-racking since I was worried about not knowing what machines to do, how much weight I could handle, etc. On top of worrying about what everyone else thought of me.

My advice is to start on some cardio, see how long you can go comfortably, then grab some free weights and start doing some curls, to gauge how much weight you can comfortably lift. Once you get more acquainted with things, start wandering around to different machines and trying some of those out. Confidence can be a big part of getting a routine down so the more you do, the more you want to do, you know what I mean?

Maybe you really enjoy ab workouts. In that case, I would grab a mat and do some calisthenics type of exercises on the floor like crunches and sit-ups. Where you begin is mainly where you feel the most comfortable.

Once you get used to the whole space and what your gym has to offer, you can start branching out. Doing more of a variety of cardio, calisthenics and weight lifting. Then adding more weight or walking/running for longer periods of time.

Pretty quickly, you will start noticing progression, even if just a little at first. Do not be discouraged when you do not see any sort of difference in the beginning. Gaining noticeable muscle or leaning down can take a while and depends on several factors including your BMI, intensity and frequency of your workouts, your diet, etc.

Another piece of advice is do not compare your routine to others. This kills motivation and progression quicker than anything else man. Just settle into workouts you enjoy doing, while still pushing yourself harder each time. Once you see the benefits of having a routine like this, you will find yourself not wanting to stop!