A missed serve is called a fault. When she/ he serve is a fault if the server swings and misses the ball
a service fault in tennis is when you either when you serve and you don't get it over the first line OR you get it out
no. if you do it's a fault.
It is called a fault or if you do it again it is called a double fault.
If you were referring to foot fault, foot fault is when serving you foot steps on the baseline or if it crosses the middle of the baseline. If you do commit a foot-fault, a serve is taken away from you; i.e if you make a foot-fault on a first serve you have to hit a 2nd serve and if you make a foot-fault on a second serve, a double fault is given.
Yes, it is a service-fault. If it was the first serve, you take your second serve; if it was your second serve, the point is awarded against you in the game.