Help setting up file sharing


ive purchased infuse currently on trial to see if i can get the hang of it and kinda struggling with setup.

ive managed to get a few folders set up on my imac but struggling with my macbook - both to work with apple tv 4k

its telling me wrong username and password

when i set my imac up i checked file sharing, added a couple of folders inthe shared folders. I wasnt sure what username and password so i used my name and my computer password and it worked.

im trying the same on my macbook now and it wont accept it, saying username and password are wrong.

not sure how to get this ?

can anyone help please

many thanks