There are two situations, either you are not suitable for doing ordinary push-ups, or you are doing something wrong and your mind is not on your chest. To put it bluntly, in fact, your plan is only for primary school students. What we want is professional full-body exercise, even if there is no professional guidance and equipment, we need professional practice.
Let's talk about it. In the first case, you should exercise all over your body. First of all, you should understand that chest exercises are divided into five parts: the lower chest, the middle chest and the outside of the middle seam. No movement can be practiced at once, so you can't expect ordinary push-ups. In the second case, the basic movements can be found online. I won't say this. I will focus on the following points: use a wide distance, move slowly, press down to the bottom for a while, and push up to the top to tighten the chest muscles for a few seconds.
Finally, the attachment is a detailed plan of unarmed body, and there are some graphic and video tutorial materials to facilitate learning movements.