Stick to solids at first.. Woven silk, grenadine, twill, diamond weave, doesn't really matter. The important thing is that the ties are clearly solids as solids go with everything and are the foundation of your tie wardrobe. I prefer anything but a plain woven silk as I find a bit of texture adds something, but this is up to you.
As far as colors are concerned, I'd want black, navy, silver / grey and burgundy to be my first four. Perhaps not exactly exciting, but they're the most versatile and essential ties you'll own.
After you have these basics, think about the types of shirts you wear most often. A light blue solid is absolutely stunning with a white shirt but not super useful for blue shirts. Green looks great with blue (also with lilac) but not as good with white shirts. A midnight navy tie with pindots or a subtle pattern will go with both and I think is without doubt a top six purchase.
My choices would be the midnight navy pindot at #5 and whichever of the green (prefer darker green, either solid or with a subtle pattern) or light blue you'd consider most useful at #6. Now you have six versatile and subtle ties which you can wear anywhere without attracting too much attention. After this, you can get more colorful (pink, lilac, burnt orange, yellow) or continue to play it safe by opting for subtle patterns on dark grounds (tasteful stripes could here).