Ok so ive had wow for around 3 months now and i started playing the random characters , then i found out that some races and classes were better than others and so on , i just want to know how i can make sure i stick with jsut the one character instead of having 10+characters and switching of them all the time. I do not want the answer : "Just play a character until lvl 10 then switch and stay with the one you like best , i need to be advised a character that is right for me , i hope you can help , thanks

So what you are saying is that you are unable to think for yourself and literally need someone to hold your hand when picking a character? Make a night elf hunter. Sounds about right for you. 
 
Race/class combinations almost don't matter. If you are really, really hardcore into end game pvp then humans have a really useful racial ability, but it isn't so great it breaks the game. Most racials become moot points by the time you reach max level. Go with a race you like the look of. I can't tell you what class would be best for you because you didn't provide any information on what kind of play style you prefer. No one class is clearly better than the others, don't believe people that say otherwise. They all have their strengths and weaknesses.

Choosing a race is largely an aesthetic choice, but it also depends on what type of character you want to make. If it's a mage, races like Blood Elves and Gnomes start with more Intellect, whereas Taurens are a great choice for tank classes due to the health bonus. Do some research into the racial abilities of each race (possibly even trying them out, as they're unlocked at level one), and go from there. But like I said, race doesn't make too much difference on anything other than what your character looks like.

@IBurningStar:

ur advice is right，very thank u

@ShadowConqueror:

very thank you,may be Just as you said, should not be to the opinions of others as the criterion. I must have its own personality