Most cost effective way to stream

hi, am trying to reduce entertainment costs i am paying as an owner. Been suppying tv services through Spectrum in Wells Maine

After doing some research, i think i might have a plan.

I believe you can just have internet and Roku. How does one get a list of all the free channels?

Would i need to populate a whole bunch of channels or is there a way to prepopulate the free ones?

I also believe premium channels like Netflix are available as long as you have an account.

Thanks for your help.