Level 7

A league with a Step 7 Premier Division with lower leagues available also would be the perfect place to start

One appointments officer to keep across admin with and you’ll get a mix of middles in the lower divisions accompanied by lines in the Premier (which will have L4’s in the middle)

Personally wouldn’t recommend joining the NWCFL with little to no experience as an AR or open age football generally.
A&H International
One appointments officer to keep across admin with and you’ll get a mix of middles in the lower divisions accompanied by lines in the Premier
I almost feel like this is key, because my first lines would no doubt be in the lower divisions, but then I'd work up and start taking Div 2 middles as well, which would be the perfect intro.
It may work differently depending on your location and number of referees on the league.

Where I am, my local county league is the Cheshire League, which is where I started refereeing open age football (bit late to the party, starting at 29 - but it’s a league I was familiar with having played in it for over 10 years and no appetite to do junior football)

The Cheshire League has 5 divisions, with the Premier Division being a Step 7 feeder league to the NWCFL (so has L4 referees with NARs) - the other 4 divisions have solo referees and you can do any division as a L7-L5.

I started by being given lines on the Premier Division, then introduced to middles in the Reserve Leagues - usually 2 of each a month assuming a month with 4 Saturday’s and available for all.

Once I grew in confidence and experience, having had feedback from L4’s and other experienced assistants (plus a couple of Observers) - I then joined the NWCFL as an AR, giving one Saturday a month to them, plus midweeks and the remaining 3 to Cheshire.

As was earlier mentioned, you’ll need to be on the ball with admin if you join the NWCFL - closed dates in 2 months in advance (e.g. December closed dates would need to be submitted by the end of October) and you could be appointed to a game on any given day that’s open (even at late notice) - if you can’t do a game you’re appointed to or need to close a date after the appointments are out, you’ll need to have a good excuse - it’s semi professional football so admin needs to be spot on. If your date is open and you’re given a game on a Friday afternoon for the Saturday, saying you have a game on another league won’t be deemed a good excuse and they are also entitled to cite Order of Precedence.

NWCFL is a great league with some brilliant clubs and grounds - but it’s definitely not for the feint hearted or in my opinion, a place to be dipping your toes in to open age football for the first time and learning the initial ropes of running the line - up until a couple of years ago you had to be a L5 to be an AR on the league, I believe it’s only fairly recently it opened up to L6 & L7.

However, once you’re there, the experience you’ll get and amount you’ll learn are second to none.