In the US there is a "grow a row" program, where you talk with local food banks (and supporting orgs) to find whats in demand.

You can also check out !NoLawns@slrpnk.net

I just redid the wiki recently to match the Reddit wiki so you no longer need to go to Reddit for the good info. I'm not sure where you live but I'd see if you have any native plant groups around you. The US has wildones.org which has some pretty great info on their website.

Avoid planting anything new for the first year. Listen to the garden and see what is has amd what it wants.

See if there are master gardeners nearby.

Garden planting time is already over so you can't plant much this year since it's July. You can plant some quick growers that are cold tolerant potentially but you missed most of this year. Which isn't a problem because there's tons of prep that you can do next year.

I would recommend reading some books about permaculture or organic gardening to get some basics but you are going to be basically growing your soil this year which is the key to sustainable good gardening. If you a spot in mind you can start Sheet Mulching right now. You can mow down whatever is there and cover with cardboard boxes (great use for those moving boxes) and then start covering with more material throughout the year. This a great way to start. You can also start Solarizing a place if you want to seed. If your in North America fall seeding works amazing for natives and it takes a few hot months to kill all the weeds seeds from a site so it's perfect to get started on it.

As far as engaging community start by contacting master gardener programs which usually have regular meetings. You can also give your extra vegetables (next year) to your neighbors which is a great way to build connections.

Look up books and guides for native plants in your area. Get as hyper-local as you can for what species to leave be, weed, or plant. Ideally in that order: it’s best to start by encouraging what’s already there by removing its nonnative competitors. If your garden is just a desert of monoculture mowed grass, exciting news: you get to kill your lawn! Check out all the fun ways you can do so here: https://weedcut-new.ipm.ucanr.edu/management-practices/#non-chemical California-specific resource, but almost all of these methods will also work elsewhere. This can be a fun way to bring people from the community into your garden, especially if you offer food and drinks.

If you have established bird feeders in your yard you could host bird watching social hours. An elevated platform for peanuts/corn/mealworms, a seed feeder, and a suet feeder should attract a wide variety no matter where you are. Don’t be discouraged if the birds take a while to notice them, just keep the feeders clean and free of mold or pests.

In that vein, there are lots of social things you could do in a garden! Gatherings for mending/repair, handcrafts, creative reuse art, and general wellbeing activities like nature journaling are all things you could do to bring people in and use it as a community space.

Look up what native plants pollinators love, and what native food plants will grow.

Grow those.

Are there already community gardens in the area? Check those out for ideas, tips, new friends.

My (haphazard and minimally informed, but fairly effective so far I think) technique has been:

• Buy some seed balls. I got https://seedball.co.uk/product/bee-mix-bag/ and https://seedball.co.uk/product/annuals-mix-bag/ and scattered them liberally around the garden during the house-warming party. Not sure if any of these actually came up, but probably a few did! (Or I just got very lucky with some random things appearing)
• Use the app from https://www.inaturalist.org/ to identify what comes up. If not local and/or not good for pollinators, onto the compost heap it goes.
• Pull up half of anything that is threatening to take over (for me it was Green Alkanet, which has many things going for it, such as being an early pollinator, but was just totally taking over)
• Throw around some more wildflower seed that a friend gave me
• Think about buying some Yellow Rattle, to really kill off the lawn - https://www.wildgardenseeds.co.uk/WF%20Plant%20Notes/Yellow%20Rattle%20Fresh.htm
• Enjoy watching the garden grow, recognising that I am only its gentle assistant rather than trying to have any major power over it.

I've also planted some rhubarb, raspberries, rosemary, strawberries, and a few other bits, because I figure there's space for some tasty things for humans too.

Just one small thought to add is that you might consider sculpting/pottery as well. It would be a great addition to the garden and if you got good maybe you could even host classes as well.

Depends a lot on what you want from it. Trees, hedges, shrubs, plants?

My garden is mainly shrubs because its quite small. If I had more space I would add fruit trees.