Hello and welcome! Just to warn you, this post is in the wrong section and as such may be moved by a moderator.
The best way to see if a snake is male or female when they are hatchlings/young is by having an experienced snake handler or breeder "pop" them to see if they have hemipenes. When they get past this young stage, they are instead probed with a special instrument (so it will not harm them or make them uncomfortable).
Usuall;y when you buy directly from a breeder they will have already sexed them, but you can always ask them to double-check.
To avoid risking injury, it is best to leave it to people who have experience in sexing snakes (although if people eventually get into breeding they tend to learn themselves, at some point - but again, there's that experience piece involved).
If it is necessary that you get one sex over another for future breeding purposes, keep in mind females tend to be slightly more expensive than males (not usually a big deal with young ones, though).
Personally, I believe gender is a cultural construct, and for snakes especially you will not find a difference between sexes but rather individual personalities of snakes themselves.
If you prefer females that's fine, it's your choice

obviously. But either way they make great pets and both get to be a similar size as adults.
Best of luck, and do take a very good look at the care guide on the main page. Getting your set-up prepared well in advance of your new snake makes for a better transition for both you and your new friend.