How to convert a c# code to unity

I have a code for uno game in c# and i want to put it in unity and make it work but i dont know how

no easy way to do this, you just habe to do it manually.
for example lets say that you coded a card, in unity that card may habe to be a gameobject so you must create it in the editor and so on.
if it is your first time in unity you should check the beginers tutorial, its so much more to it than code.