Like everyone else stated, pick what looks good to you.

When do you want to start breeding?
If sooner, then I would start buying adult/young adult females. It will be more expensive this route though with each female going for 1k each or more depending on the morph. Females gain value as they reach breeding size.

If you want to save thousands of dollars, then start with single or double gene female hatchlings. They will take time to grow though. It takes the average female hatchling to reach sexual maturity by 2 years of age or more.

I wouldn't even both with males for another year or so. So that gives you time to think of a breeding plan. Also, desired males may come down in price by then. I would go w/ at least double gene males.

The upfront cost will be more for multigened animals compared to single gene, but it will be more efficient in the long run. Less housing, less mouths to feed, less time cleaning, etc etc compared to if you wanted 2 single gene snakes.

Pastels, Lessers, Cinnamons/Black Pastels, pinstripes, and spiders are the more basic starter genes.

Do you want a recessive project? Albinos are classic. Hypo/Ghosts are one of the cheaper recessives, but put out one of the more beautiful combos. What about Clowns?
If you plan on a recessive gene project, then I suggest investing in a morph het rather than just a normal het. For example, pinstripe het albino rather than a normal het albino.