Everyone’s goals are different and yours will change over time. My philosophy is to always add intensity first and time second: you’ll get more out of a shorter, but more intense workout than you will out of a longer, more moderate workout. To get faster/better/more effective results on a spinner, your best bet is to train for speed: improving your time for a specific distance.
For example, if you can do a 5K in (hypothetically) 20 minutes, your goal should be to try and beat your time. You can also flip it around and try to improve your distance for a specific time (let’s say you’re able to cover 15K in 30 minutes. You goal could be to hit 20K in the same amount of time).
From now on, be sure to keep track of what you did (distance AND time) and use that as your benchmark for each workout. Not only will it give you a goal to work towards, but it’s WAY more motivating to SEE how far you’ve come. Some workouts you’ll want to focus on speed, and every now and then you can focus on endurance too: it’s up to you. Adding short, quick high intensity intervals is another way to make your sessions more fruitful, even if you keep a moderate pace the rest of the time.
Of course, no program is complete without some strength training (and flexibility too). Make sure you’re hitting the weights or adding resistance at LEAST a few times a week: you’ll see better & faster results with a combination of the two. Invest in dumbbells, resistance bands or stability balls to add to the program. Yoga is a great option for flexibility, but even extended stretch sessions after each workout will improve your flexibility. Stretching is best done warm. :)
Hope this helps! Don’t forget to try something new every now and then!