edit:this got longer than I expected.
TL;DR: find a group doing anything on a regular basis, take photos of them on a regular basis, get to know them - benefit.
As others said, it depends on the event. Don't just go anywhere and take photos. Inform yourself or speak to someone and if there are professionals, don't stand in their way.
I suggest you to find a local club of anything. Don't know where you're from and whats popular in your area but you might know someone who goes to soccer practice or maybe is a fan of a sports team. Seek out a contact to speak to. explain to them, that you are an amateur photographer working on your skills/portfolio. Let them use your photos. Most of those players/participants will be thrilled to have some action shots of themselves doing their favorite thing. They will want to use your photos for instagram or dating apps etc. You will get to know them and all of them will know the photographer after some time. Maybe one of them works somewhere, where they need a photographer, maybe he likes your pictures and hires you etc. a lot of those players may marry someday and will need a photographer. you see where this is going. You can switch soccer with anything else you are more interested in. Learning to shoot Sportevents is at the same time some of the harder event-jobs. So you're learningcurve will be huge. Maybe you're not into sports at all. Think wide here, anything that happens on a regular basis (so you get to know ppl and get in practice), is not pro enough, to have a photographer and has a group of people participating works.
Maybe it's a theatre group, maybe it's a group of friends bowling.
I did something similar 8 years ago with and work as a professional Sport- Events- and Commercial-Photographer ever since.
Maybe you're not into sports at all, as I said. It can be anything. It's the advice I give to anyone whos asks me how to start as a photographer. Get in practice and get to know a lot of people.
When you work on a professional level your skill will max out at some point. You will take pictures on the most professional level, there is a lot of photographers who take photos on the same level, from that moment on contacts is the second most important factor in getting jobs.
edit:this got longer than I expected. TL;DR: find a group doing anything on a regular basis, take photos of them on a regular basis, get to know them - benefit.
As others said, it depends on the event. Don't just go anywhere and take photos. Inform yourself or speak to someone and if there are professionals, don't stand in their way.
I suggest you to find a local club of anything. Don't know where you're from and whats popular in your area but you might know someone who goes to soccer practice or maybe is a fan of a sports team. Seek out a contact to speak to. explain to them, that you are an amateur photographer working on your skills/portfolio. Let them use your photos. Most of those players/participants will be thrilled to have some action shots of themselves doing their favorite thing. They will want to use your photos for instagram or dating apps etc. You will get to know them and all of them will know the photographer after some time. Maybe one of them works somewhere, where they need a photographer, maybe he likes your pictures and hires you etc. a lot of those players may marry someday and will need a photographer. you see where this is going. You can switch soccer with anything else you are more interested in. Learning to shoot Sportevents is at the same time some of the harder event-jobs. So you're learningcurve will be huge. Maybe you're not into sports at all. Think wide here, anything that happens on a regular basis (so you get to know ppl and get in practice), is not pro enough, to have a photographer and has a group of people participating works. Maybe it's a theatre group, maybe it's a group of friends bowling.
I did something similar 8 years ago with and work as a professional Sport- Events- and Commercial-Photographer ever since. Maybe you're not into sports at all, as I said. It can be anything. It's the advice I give to anyone whos asks me how to start as a photographer. Get in practice and get to know a lot of people. When you work on a professional level your skill will max out at some point. You will take pictures on the most professional level, there is a lot of photographers who take photos on the same level, from that moment on contacts is the second most important factor in getting jobs.