Crepes have no baking powder in them.
No, Pillsbury refrigerated biscuits do not contain yeast. American style baking powder biscuits are leavened with baking powder and baking soda.
baking powder
If by 'bakers flour' you mean self rising flour, the answer is no. Self rising flour has baking powder which causes it to rise. With crepes, you want them to stay thin and delicate, not to rise and have a bread-like consistency.
yes
I am assuming you are out of baking powder? If you have baking soda and cream of tarter, you can substitute that - 2 parts cream of tarter to 1 part baking soda. Use the resulting powder in the proportions the recipe calls for. Alternatively, you can beat your egg whites in the recipe (I might add an additional egg white for extra leavening) and fold them into the yolk/milk/flour mixture. Or you could just make crepes - omitting the baking powder and making a denser, flat pancake, a la Paris!
Baking SodaBaking sodaBicarbonate of soda
Baking powder does contain sodium monophosphate but usually also contains sodium bicarbonate, potassium tartrate and sometimes corn starch. Baking soda however, is pure sodium bicarbonate.
Bread recipes can contain various raising agents, such as yeast, baking soda and baking powder.
The first thought is that one may have forgot to add baking powder, or not enough baking powder or the baking powder was bad. Baking powder is perishable. To test a batch, add 1 teaspoon to ½ cup hot water. If it doesn't bubble, throw it out.
There are several foods that contain baking powder. Many breads, biscuits, cakes, cookies, and other food items contain baking soda.
Most are made with yeast, so they don't contain any baking powder.