Hey guys, i just got my black moore goldfish today and its so nice and preety, awesome fish IMO , i have it in a 10 Gallon tank, the starter kit that can be bought from petland discounts , i have put blue gravle along another rainbox gravle inside nicely, i have put a "No Fishing!" toy decoration kindda thing which is really cool

and i have put 3 artifical plants there which are cool i guess, i have put stress coat and the other coat which i forgot the name of, i got the sample 1 time use that u put when u setup the aquarim the first time so i didnt buy them yet so i dont remember what the second coat is called, anyway i have also a hood with yellow lights, looks great.i have a few question, the black moore goldfish is the only fish i have right now, he is kindda lonely there as far as i can see so i want to get him another orange goldfish in his size on friday, thta will be okay right? i was told to give the black moore goldfish food only in the morning, im feeding him the food that i got with the kit, goldfish food that it, the small leaves kinda food, i heared taht they like lettuuce too, is that correct? what else do they like? and do i have to chop it real real small so they can it it u kno? and 1 more question, is it ok if i turn on the light at night, i mean does that affect the fish'es vision, i assume it does? or should i just live the light on in the night and turn off in the day?
please assist and thx for having me on this lovely forum!