Creating a custom post type for Sports Text codes HELP

Hi, I am trying to figure out how to do this! I know how to create basic custom post types but I’m not sure how to do what I’m wanting to do. I want to create a UI in the admin to enter text codes for different teams. How I’d like to enter the data is as follows:

Select box for League (NFL, MLB, NBA…)
Based on which league is selected another drop down menu shows up with the Team names for that league.

A text box for entering the Text-code
A text box for entering the Hotline
A text box for entering the Instructions

Where I am really running into an issue is how do i display the drop down to choose the league and then make the second dropdown for the teams appear?

i’m assuming that i need to use taxonomies for this in some way but i’m not very familiar with how to make this work.

Any help would be AWESOME!!!

if you go to https://www.fansagainstviolence.org/game-day-hotlines/ You’ll see how i’d like them to show up, but i really right now I just have them entered in the editor..I’d love to be able to just add codes as I get them through a custom post type.

If anyone can point me in the right direction I’d appreciate it!

Thank you!
Kathy