Derek, Best wishes on this venture. You will enrich many lives!!
Consider making up complete Square One books from the ringer edition, one for every 1 or 2 ringers, instead of handing out loose sheets for each lesson. This makes life so much easier. And no filing at the end of the year! ...Or, if you can project each page on a screen, even better - and cheaper. I put the "Find Your Notes" on the front of every book and position # on the outside front, so kids can always check their position....and the notebook flip-up cards with ringing positions are also great to use.
If you have up to 22 in a class (which sounds possible) - and you are short equipment - I'd make position partners (1A and 1 B at CD4) - they share the same pair of bells. Explain and rote practice everything once, but play through everything twice for ringers 1A and 1B to both experience the music. Have the non-ringing person tap or pat the notes (L and R hands) to keep the learning going.)
Chord Stories (for your youngest ones) can accommodate up to 22 ringers - each plays 1 or 2 notes as part of a character in a narrated story. This is a good instant ringing experience.
I can send you some reproducible music. Need your address.
The Guild used to have an event scholarship grant (I got one for a Youth Festival, once) - which might give you a boost to get some equipment and materials. There's also a new Educator's fund, but I don't know much about it. Your local Arts Council may also have grants available - timing is crucial for applications. And perhaps a local ringing group would help sponsor a ringer or some equipment..or donate some old pads, etc. Almost everything I started out with at my school was donated or loaned, which saved me!!
Need anything more specific, let me know.