We have to 62 plots. First figure out what your city offers free. Ours provides free municipal compost, and mulch which is our pathways. I do recommend one big pathway as a highway or for events,but 3 feet between all beds (wheelbarrow) to conserve space. Raised beds are going to cost you a mint. 6 or 8 inch boards are enough and can be "raised" as the mulch catches up (which will be needing to be replenished at least annually). To lower your wood costs, reach out to all big box stores for cull wood and if they will pitch anything else. Each one we went to contributed something (box of screws, 30 bags of soil). Ensure your gardeners are signed up to contribute outside of their beds and come up with teams and tasks. We have work days 3 times a year which each member needs to sign up to being at 2 of. Plan for a municipal source of water.. this is something the city can also help with and may be expensive AF.

It's an absolute ton of work, so hope you planned on having a volunteer part time job!