Are you a girl? It is very unlikely that girls will not float. The density of human body is similar to that of water. If you take enough breath, hold your breath and don't spit it out, then your chest will bulge and people will float. If you lie still, some people's legs will gradually sink, so that the human body will gradually tilt and sink like the bow is tilted and the stern sinks. This is because some people have well-developed leg muscles, while upper limbs have more fat and less muscles. Because the density of muscle is higher than that of fat, the human body floats in the water like a balance, and the result will tilt and sink as mentioned above.

People whose leg muscles are far more developed than those of their upper limbs are often boys, such as those who like playing basketball and football. Girls rarely do this, because girls don't like sports, they often have more fat in their lower limbs, and their upper limbs have to do some work, so more than half of them can float directly.

So you have to identify whether your so-called inability to float is caused by the sinking of my lower limbs, and if so! Your learning process will be more difficult! If not, there is only one other possibility. You haven't breathed enough. Some people still keep their usual breathing habits when swimming, that is, exhale immediately after inhaling, or hold it after exhaling. This is not right. When swimming, you breathe in and hold it. If you can't hold it, just exhale and inhale. If you inhale, hold your breath. When you hold your breath, you should be able to clearly feel the chest expanding! Only in this way can it float.