That depends on what type of training you're wanting. If you're circuit training, aim for machines that target a different muscle group and alternate machines between sets. If you're going for muscle isolation, you'll want to find multiple machines that target a specific muscle group (so back, shoulders, legs, bi/tri, chest), hit roughly 4 sets x 8-12 reps per set with 45-90 second rest intervals. If you're a beginning, then you'll probably only want to perform 4-5 excerises per workout (4-5 machines) and work out at least 3 days per week or a max of 5 days per week.

All of our workouts are without machines unless you have an indoor bike and can do the Power Cycle program.
https://grokker.com/fitness/cardio/program/power-cycle-with-vanessa-wilkins/562fb00c2943fe8749a466e0