Generally speaking it takes many years of hard work and dedication. There are very few people that become champions in a few years. Boxing is a very lonely sport. Its the training and consistency of same that will take you were you are going. The fight is the easy part. It is the behind the scenes activities you do not see that are the factors.You also need to live clean no alcohol smoking or drug usage. You have to be well rested. Also you have to be focused mentally. It takes a very unique and special individual to succeed in this sport. The day in day out discipline and training is what most people cannot handle.

Depends on how fast you climb the rankings. For some it takes 20 or more fights. For Leon Spinks it took only 7 fights to get a shot at Ali. The promoter also has a say in it.

It really doesnt take long. Not unless if you're Lomachenko.

how hard do you want to train and how much do you want to be the champ.

Leon Spinks became a champion after 7 pro fights, but lost in his next fight and never was the same again. Some fighter's take years and many, many fights before even getting that title shot. May depend on the division you're in, the country, and of course your boxing talent and record.

Depends on how good of a boxer you are.