Congrats on getting a brb, you won’t be disappointed at all...
I’ll try not to go over points already made, but I do want to reiterate about them being a shy species. Offer lots of cover inside the enclosure and as has been said you want 80%+ on humidity. I find they feed far better once the lights go down but also become quite bitey as well at night... so I keep feeding to nights and handling to daytime.
Personally, if you can’t sex the snake then I’d say hold off on getting another as you’ll have a 50/50 chance of getting the right sex... You’ll have plenty of time to pick up a second one as this one grows to size and then you’ll at least know what sex you need.
Also, be careful with popping and probing to find out the sex... It’s very easy at that age to hurt them doing that and also it’s possible to injure the sexual organs and that’ll cause issues later on when breeding time comes.
Good luck, keep us all updated as you get on.... And I’m sure we’d all love to see some pics of your new addition!