There's really not that much to starting a club per se, especially if you are only playing casual. Just make a club in NHL 22 and invite some friends and get playing.
If you are looking in to going for tournaments you need to make sure that the whole team is committed to playing on certain dates (at least the scheduled games) or having enough backup players. At least 8 players are required and 14 was the cap if I remember correctly. If you are not able to play the scheduled days and you can't find a replacement date for matches (within the given timeframe) you will be forced to forfeit a.k.a give walkovers to the other team, and may be subject to a ban from future tournaments.
Creating a team is easy enough, but managing 8-14 people is a bit harder especially if they are not that committed or have busy social/worklife.
Also keep in mind that most of the ECL tournaments have teams from northern europe so the home matches of those teams will be played on the north europe servers, which mean that you are going to have a worse connection. The connection is PLAYABLE, but significantly worse. Ofcourse the workaround to this is to play only tournaments that are played mostly on servers closer to you.
After all this, if you are still interested in creating and managing your own team, go for it! It can be most rewarding, there's no feeling like it when you win as a team, but it also takes alot!
Hope this helps 😁
ps. ECL NEO is good if you are looking to start your own team and playing somewhat competetively.