Activity for Rosa

I have decided to have my wedding at Yosemite in Cali, the park is beautiful and I will be doing a picnic wedding receptions, my fam and friends will be helping with the food, does anyone have any ideas for the decor, party favors, centerpieces,...

Ok, I finally decided on my venue, but now am having trouble deciding things for the reception, i am on a tight budget and was thinking of doing a picnic reception. Does anyone have any thoughts or ideas???