Depends on how much you need to raise and for what. We've had loose change jars where members of the congregation dropped in the coins that were sitting around their houses doing nothing. When the minister fell on hard times once, we had what we called Pound the Pastor, where everyone donated a pound of something--a pound of quarters, a pound of rice, a pound of hamburger, etc.
What do you need the money for? What kind of funds or other resources do you have for start up?
You may have $0 cash but have access to the church printer (posters/flyer) or a church kitchen and hall.
Do you have an enclosed/ fenced in area? How many workers are willing to donate their time?
What kind of hours are they willing to be available?
This is the sort of thing you need to know so that you can for a plan with all the people who will head up this project.
Some ideas are baking goodies and having a "social" You will need confirmed donations and plates . napkins, servers, etc.
One afternoon of summer fun for kids (like a day camp)
This was especially good before the holiday. Kids made cookies or a craft and parents could shop.
Contacting local businesses, especially ones in your church. Spread the word to come on a certain day and hand in a coupon for a cookie with your meal and the church gets a certain par
Have people sponsor church members for a certain event.
I was making baby quilts for a charity sponsored by our church. I had too much fabric and time. I got sponsors how pledged a certain amount for every quilt I made in one month. They were warned how fast I could quilt them. It is the binding that hung me up , time wise.
The tops were whole cloth. Each day the finished ones were put on display and they piled up. I got a donation if I would do the quilting after church so others could see it. There was a jar for donations if anyone wanted to drop in coins. In the end there was a pile of quilts for charity. The quilts were then taken to the babies in crisis center.
This maybe way involved for you but you can go with as many people as you can get or just one. It depends on what you are looking for.