I don't know how many push-ups you can do now, so I can't give you a definite plan. But you can do it according to your own situation. For example, each group has 10 standard push-ups (it is required to get up quickly and release slowly, and cannot use force) and one ***5 groups, with an interval of 30s to 1min.
If you think 10, reduce the number of times to 7-8 or even less, but increase the number of groups by 1 or even more. In short, the total number of push-ups in these groups should not be lower than the target number. (The higher the number of groups, the less the number of times, which is more conducive to muscle gain)
If you feel that just doing a few things is not enough, increase the number of times in each group until the chest muscles feel sore. However, the number of groups must exceed 3. [High frequency (such as 30/50 push-ups) can exercise endurance, which requires more muscles and heart and lungs]
Exercise chest muscles every week 135, and exercise arms, legs, shoulders and back at other times. If you feel a chest strain and it hurts, wait until you get better.
Relax fully every time you finish, then replenish energy, eat some bread or something, and replenish protein in half an hour. If possible, drink protein powder/muscle powder, or drink milk and eat eggs. I suggest you add more meals to yourself at ordinary times, eat a fruit and get some snacks when you are free. If you do more exercise, you will find something to eat with an empty stomach.
When you have a little foundation, you can also practice your chest muscles with dumbbells. Take your time, stick to 1 month and you will find changes. After that, it's easy to form habits and practice. You can learn a lot by visiting Baidu Fitness Bar when you are free.