I dont no ifi shud buy a car b4 i get my drivers license to pratice more in with my mum? they think bad idea?

ive been doing my driving lessions on and of since i was 17 i am now 21 they think im ready for my test bt i dont have that much confidence bcz its always been on and of i was thinking about buying a car to pratice more in bcz driving lessions are 2 expensive now and i cant always afford them.. some ppl are sayin get ur licence b4 u buy a car and other friends are sayin get the pratice in ur own car lke my friend did it and she ped. any suggestions please.. thank you all.x