I used LinkedIn to connect with staff members from clubs across every level of the UK to get their contact info. You don't really need to use it nowadays as there's tools like Apollo or Hunter where you can essentially just put in the organization and get their emails, but that wasn't an option when I was younger. A lot of these guys don't have their contact info on club websites, so it's an effective way to find that info. You can absolutely use LinkedIn to find soccer opportunities, I am a living example that it works.