Hey,
Im new to this game as my friend suggested the game to me and i would like to know what the best and quickest moves are to play well at yellow belt. All help is appreciated.

...Pressing space when your done with making your move...

you dont have to be at a high belt to do good things, just make sure you dont use symmetry, i highly recommend not using it, in single and multiplayer.

Well this question has only one really good answer.

There are no 'best' moves. All moves can be countered, it's not always easy though.
I assume your searching for a starter. Starters are very mod-based(The mod you play needs a specific starter). I'll give you a few pointers on a couple mods.

Judo:
-Try to hit your opponent while not letting them hit you. (grab their hands usually works well) As well as use a combination of glutes, hips, and knees for a basic kick. Judo has a low dismemberment threshold, which means the limbs break a lot easier.

Aikido:
-Find a starter that suits you. For me i use a very simple starter. When you find one that you like, use it. Practice with it until you know how it works. One thing that you'll find in aikido is that people hit the ground very often. This can be avoided with your feet. Always try to have your feet in close range with the ground. Because this can help you stay up, which, in most cases will help you win.

For TK(teakeyn mis-spell?) or Kb(kickboxing)
-Im not the guy to ask. sorry =\

Wushu:
-For wushu, it helps to learn a basic starter. One that will get you over to your opponent. You can probably look on youtube, or ask someone in-game. Most people are nice and will probably help you. Once you have that starter down, it's up to you, you can go back on youtube and learn more starters(not recommended). Or you can make your own starters. After you grasp the basics from the first starter, it shouldn't be too much of a challenge. Just a lot of trail and error. ;)

Just post if you have any more questions.