Bride on a budget !

I would look up via pinterest. Try this link here: https://beautyofwedding.co/11-cheap-wedding-reception-food-drink-menu-ideas-on-a-budget

Take a look at local parks or community centers for reception venues. Eventective.com has ideas as well.

Decide on your must have guest list. Only you know who you want to invite and their relationship to you.

Make a list of top 3-5 most important things to focus on. Skip the rest.

You can go simple with cake and coffee in the afternoon or serve a full meal. Having your favorite restaurant cater will be much cheaper than a wedding caterer if cost is a concern. Depending on your venue, most require a licensed caterer which a restaurant will fit into. Grocery stores have delicious cakes or serve a dessert buffet instead.

Alcohol will break the bank so decide if it's important to you.

Take a look at Vistaprint for invitations.

Costco can provide flowers.

Ask a photographer if they can give you hourly rates.

DIY is not always cheaper because your time and sanity factor into the money aspect as well.

Renting items will be cheaper than buying them because you won't have to spend time and stress trying to rehome stuff afterward.

It sounds like a lovely little rustic wedding and I think given the setting, you should look to do something fun for food like hire a food truck. Since it isn't a razzle dazzle glamorous do (correct me if I'm wrong here), I think something like a hotdog burger truck would make people really really happy (I personally will choose a burger any day over a wanky plated meal) and will possibly be cheaper than a caterer.

Cake is also another one you can save lots on - make it yourself or see if someone in the family can.

Depending on how easy/expensive it is to become a celebrant, maybe have a close friend or relative become certified and marry you and FH?