You need a Roku for each device unless you have a newer model Tv that is already internet enabled.
And your speeds won’t cut it. :-( Negotiate for something better!
one streaming device per screen.
My Roku and Netflix give me the most viewing enjoyment that I can remember.
I gave up television decades ago, since it simply didn’t interest me much.
Now I get Wallander, English and Swedish televison serials, for example. Lillyhammer was funny.
I get numerous British murder mystery/crime procedurals such as Foyle’s War, George Gently, Cracker, to name a few I’ve enjoyed.
If anybody worries that Netflix has raunchy stuff, forget about it. It has adult language, but it is in the films.