Morning everyone. There are lots of great tips on here so far, but the very best advice I can give is to
1) Cleanse (Micellar water is perfect and you can get some for sensitive skins
2) Tone - use a toner for sensitive skins which doesn't have to be an expensive one
3) Moisturise - use a moisturiser which is suitable for your skin e.g. dry, oily, combination, fine lines and wrinkles etc.
4) Use a richer moisturiser at night, preferably one which contains vitamin E as the skin needs this vitamin to repair itself, which it does at night.
When you have a good skin then very little is needed to enhance it. I would recommend a tinted moisturiser - No 7 do a great one - because this will be light on the skin and give a fresh, dewy look. Ideal if you are not used to wearing foundation.
Go easy on the eye makeup but make sure your brows are defined - if they are sparse use a tiny brush and fill in the gaps with a suitable colour eye shadow. The eyebrows frame the face and then a lipstick - not too dark - will complete your look. If your lipstick bleeds into the fine lines around your mouth, use a lip liner in a similar colour to outline the lips with feathery strokes (not a solid line) and if you lose your lipstick very quickly, colour the whole of your lips with the lip liner and you will still have a colour on your lips after your lipstick has disappeared!!
I hope this has helped, but another tip is to always wash any brushes and sponges frequently, and change your mascara after 3 months. Keep an old mascara brush, wash it thoroughly, and if your mascara goes clumpy when you apply it, then immediately go through your lashes with the clean mascara wand. This will separate and define your lashes.
Have fun experimenting with products and I'm sure you will look wonderful.