Unicorn with Wings Request

Hello BlenderARTISANS

I am complete newbie to blender. So, as you can understand it is a bit mindblowing. I want to do some animation with unicorn with wings with green background so that I can change the background at will. I am wondering if anybody can help. Have you done a horse before ? If so, can I use the model to modify to make a unicorn ? If so, how can I get it and modify ?

If not, can I get a tutorial for newbie to get this done ? At least the steps required will be appreciated.

Thank you kindly.