Of the four skills, listening, speaking, reading and writing, which one are you strongest at? This post is mostly about listening, in case that is the one you want to work on.
Listening for the main idea
This is what you do sitting in a cafe with a friend. You are half on your phone, half listening. You will not remember every detail, but you still follow the point. You know what the topic is, whether your friend agrees or disagrees, whether they are cheerful or annoyed, whether they want advice or are just stating a view.
Listening for specific details
Now imagine you work at that cafe and your job is taking orders. You serve a hundred people a day, so you cannot attend to everything each one says. You need the details that matter: what they are eating, what they are drinking, whether there is a special request, the phone number for following up.
When you talk to a customer, you filter for the information you actually need and hold onto it when it comes.
Listening to understand something deeply
University students do this most, sitting through lectures. Here you need all the detail and you need to genuinely understand what you are hearing. The information you need usually is not in any single sentence or word. You assemble it across several sentences, sometimes across whole sections.
Do put the work into listening. Once you listen well, speaking improves quickly, because speaking is largely repeating what you have heard. And once two of the four skills are solid, the other two stop feeling so far away.