Do I need a baking stone in the oven to bake the baguette
A baking stone or steel are really helpful to get that initial oven spring that you want, so I’d say yes. You could also try with a cookie sheet, but they just don’t hold much heat so you won’t get the oven spring you desire.
Benny
I use pizza stone tiles to bake Baguettes and Ciabatta buns on. I get much better lift than what I used to get baking on pans. It takes 9 tiles to completely cover one oven rack. I have enough tiles to cover 3 racks.