A.F.
Honestly, his first birthday? Save your money: he'll never remember it. Have a cute little cake, have your relatives over or the neighborhood Moms and kids, but just don't stress out over it.
I know a lot of people are doing big fancy parties for the kids these days, but I always did the old fashioned sort of party. # of Guests= child's age +1, home made cake. simple games based on your theme, invitation stated from 1 to 2 or similar specific end time. When the kids got older (the 8 and 9 yo range) I got more creative, but I never spent much money on them, and never hired entertainment... I always felt that there were so many other things to spend that money on: theater camp, swimming lessons, Y membership, bikes, dance classes, soccer, football, the sports equipment....
your mileage may vary, but I always used the decision and the planning process to teach about making decisions, and opportunity costs.