How to choose trump color and discard to widow

[lil_birdie]

I am new here. I have searched this forum for this answer and cannot find it. I hope someone will be nice enough to help me out. I was in a game recently and placed the high bid. The game prompted me to choose color for trump and discard to widow. I could not figure out how to do it. I have not been able to find any instructions and I don't want to get involved in a game and mess it up again. I would appreciate anyone's help! Thanks