Squirting?

How do you do it? Does it just happen? Do you have to push or just relax? How do you know when you're going to? A lot of questions lol. I just feel like I need to do it during sex lately but I've never done it before. It gets so intense almost to where I can't bare it. I usually will stop and push him off or change up the position. It feels really good but different? Just something is telling me I need to?