A:Answer "Subscribing to Roku" is free. They ask for a credit card number but you don't have to give one, and it's still free.
I don't "subscribe" to things because my goal when I purchased my very first Roku, was to not pay for TV.
I don't know, since all my Roku devices are plugged into non-smart TV's but I would guess that if the Roku TV is a Roku, that they all work the same way. You would need to sign in to Roku to get access to the Roku Channel Store. When you get there, you'll easily be able to use Netflix and Hulu. Signing up for Roku - if you have a Roku device - is free.
Roku is actually built to create access to Netflix and Hulu so you would go to the Roku Channel Store and make sure that Netflix and Hulu are in the channel store. When you link them, you'll need to use either a laptop or a phone to get a code to do it - once and done.
There are abundant channels in the Roku Channel store and there are a few good ones that are totally free also, that include the Roku Channel, Tubi TV, Sony/Crackle and You Tube for example, that have even more free content.