Before buying anything, I think you should consider what you want.
Do you want makeup for a more neutral look or something a little more than that?
How much time do you want to spend on doing your makeup?
Do you want something really simple or are you keen on spending time learning how to do cat eyeliner and other techniques that might require a bit of effort?
Is there anything specific you would like or feel that you need - such as red lipstick or something to conceal bags or dark circles or spots or is there anything you would like to enhance?
Do you want foundation, powders, blusher, highlighter, eye shadows, eyeliner, kohl, lipstick, gloss, mascara or do you just want a few items?
How much are you willing to spend?
I'd suggest not getting everything from one brand as no brand does everything really well.
Also, ask for samples of foundation before buying as you will have to check if the colour is right, if it oxidises (goes darker/orange during the day) and if it wears nicely on your skin and if you have a bad reaction to the foundation.
I personally like this look for everyday wear: www.lisaeldridge.com/video/26180/fresh-faced-beauty-makeup-with-sophie-dahl/#.VAo55WMgvKc
If I was to buy a new set of makeup, I'd go for:
Real Techniques Expert Face Brush
Angled eye brush and a spoolie (which is a mascara wand) for doing eyebrows
Blusher brush
Foundation - light/medium coverage, such as Estee Lauder Double Wear Light, Mac Face and Body Foundation, Laura Mercier Tinted Moisturiser (I have the oil free one) or Diorskin Nude
Mac Select Sheer Pressed Powder (can be used to set the foundation and for touch-ups later in the day)
Chanel Illusion d'ombre in Emerveille - it's a cream eyeshadow that is so wearable both for day and evening.
Mac Mystery eyeshadow for eyebrows (also great for lining eyes)
A lipstick in a 'my lips but better' kind of colour - there are different finishes and types, so it's just about finding one that suits your preferences.
Blusher in a nice pink tone
Brown mascara
There are loads of videos on youtube about makeup, so you might be able to find something you really like which will help you when you go to the counters as you can then describe roughly what you'd like.
Wow, that's long. Sorry.