I just started working out for real about 2 years ago. Never really done anything other than noodling around and wanted to get into shape and build muscle/trim fat now.
So this is how I proceeded:
I joined a gym (long story to work up to it, but I made myself establish a regular schedule of working out/exercise at least 5X weekly first).
I started out on the weight machines, and a notebook. You'll need to figure out what your machine can do, so do lookup a booklet on the different settings ASAP. Also check sites like YouTube for your machine too, as it would be really great to see someone demonstrating the actual machine for you - they may have a site with videos if you search for it.
I established a baseline for myself. This was doing 3 sets of 10 reps each, per exercise. Rested about 1 minute in between and I made sure to take the first week or two with a low weight setting so I was getting the general idea of the movements involved first before adding in heavier settings.
I then figured out the best exercises that I wanted to do to target the main body/muscle groups - I think my list was basically things like hip ab/ad ductions, chest press, fly, row, leg press, leg curl, lat pulldown, bicep curls, calf extensions. Ran through that list each time, maybe not in order depending, alternating upper and lower exercises.
Wrote down all of this in my notebook: exercise movement like "bicep curls" then weight and number of sets/reps. So after one week, I'd figured out how to perform the movements properly, I started bumping up the weight each week. Added 2-5 pounds for upper body, 5-10 pounds for lower. If I got to a week where the additional weight was too hard to complete the full set/rep range from the week before, then I would stay there but do like 2 sets instead of 3, or 5 reps instead of 10 until I could work up to my set/rep number without losing proper form, and then advance up on the weights in another week or two.
Make sure to stretch and warm up at least 10 minutes beforehand, and drink water during. And get some cardio in a few times a week in addition to working with weights.
And do look into some body weight exercises and core stuff once you're going well at this. Machines are easier to do and isolate muscle groups, but if you add in something like yoga (which doesn't need lots of equipment - and check your area for free classes. I teach yoga for free at the local library!) it will help with core and balance too.
I still occasionally do the circuit on the machines now when pressed for time, but I really like doing free weights and am currently working on weighted squats, dead lifts, bench presses/fly along with some fun weight classes with a splash of cardio built in. Nothing wrong with sticking with the machine as long as you're also working out by just getting out there and moving too!