Find a team (preferably one local to you but can be any team if you want), get a subscription to whichever service will show your team (sky, bt, Premier sports player or sometimes teams will have their own service for streaming games like qpr+ for instance is how I watch my team, its a pay per game type of deal)
Soon enough you'll understand the situation your team is in (comfortable mid table, pushing for europe or avoiding relegation), you'll learn all the players as you watch them play and soon enough you'll be able to make your own analysis of who should be playing and who shouldn't, as well as potential transfer targets and departures in regards to strengthening the side. You should also tune in the clubs community outlets like their subreddit or maybe a podcast for all the latest on the team.
If you really don't know anything about football though I suggest just watching a few videos on the rules and maybe the history of it. It's not for everyone but once you get into it properly you'll never leave. It's one of those things that linger around for a lifetime regardless of if you're paying attention fully or just checking up on the progress from time to time. Just stay away from twitter and the horrendous takes the kids on there are spouting out