I am a budding cake decorator who wants to learn all the various cake decorating techniques. I want to get all the tools required for this trade. I would like your help to know what are the must-have tools. 

I currently have:

Cake Turntable

2 star tips 

Flat and offset Spatula

Piping bags.

Cake lifter which i am using as a side smoother

I am thinking i would need atleast:

1. A set of piping tips

2. Fondant shaping tools set

What else i am missing here? Are wiltons decorating sets recommended? I am total noob.

must-have tools? all of them 

The tools depend on the type of decorating you want to do.  I like to think my hands control most of the decorating.  I use a total of about 10 different tips to do figure piping, sculpting and buttercream flowers.  Many years ago, like in 2005 or 2006 we had a tip of the month contest and you had to decorate a cake using only one tip, of your choice.  For the month of October I chose tip # 5.  This is the cake I decorated with that tip.

that is way cool, bcjean

When I was teaching I encouraged students to practice by choosing one tip for the day and doing each and everything they could possibly  with that tip......and for some of them - like the rose tips 101 thru 104 - that meant turning it all different directions.  Do 'stars', dots, shells, reverse shell. zigzag, etc, etc.    As BCJean said, there is soooooo much that is a bit different that can be done with just a few.  Learning to decrease and increase your pressure is the key.  But OP definately needs more than 2 star tips :)   I do most of my decorating work  w/a small off-set spatula.   I also prefere applying b'cream icing w/the 'cake icer tip' - can't remember the # :(  It's 2" wide and has one edge serrated, the other smooth.  You need an 18" pastry bag to use it.  Wilton decorating sets aren't necessarily recommended but one w/about 15 tips could be helpful to a beginner.   Also, you don't need every # tip.   Like do get 1, 2, 3, then skip to 6 or 7, 10 & 12.   Definately get 352 (leaf tip); 103 or 104;  Can't remember which ones I used the most anymore :( 

one tip I loved is the 101s -- it's a teeny tiny rose tip -- but it makes your writing look like calligraphy