All you need to do to upgrade to WiFi is purchase your own router.
If you get something from Time Warner they will give you a modem/router combo unit. (also so known as a gateway)
Some people think those are the best thing since sliced bread. Others say they have had bad experiences with them.
Personally, I would never use a gateway unit.
It's not difficult to set up a router and create a network. Most of them have disk you can use which will guide you through setting it up, naming your network, giving it a strong password to prevent those outside your house from connecting to the network.
The first time I had to set up a router I was intimidated just thinking about doing it. I bought the router and let it sit in the box for a couple of days. We continued unhooking my desktop from the modem so my daughter could connect her laptop to the modem. Doing that was a pain so I decided to take the plunge. I got it all set up and IT WORKED. Her laptop no longer needed to be connected directly to the modem. It was one of those Wow that was so easy I don't know why I worried about it so much things. If I could do, anyone can.
There is a wide variety of routers and wide price range. You don't need the most expensive one, just something that is a good brand that suits your needs. My suggestion is to look at websites for stores in your area. Places like Best Buy, Office Depot, Wal-Mart, etc. See what they have available. Ask questions about them here if you have questions about any of them. Keep in mind that what they have on the website may not be available in the local store, but it will give you a good idea of brand and price. If you know the basics you can go to the store knowing what you want and if you talk to a salesperson you will sound like you know what you are talking about (even if you don't understand it all). You can avoid the high pressure attempt to get you to buy the most expensive one they have.
If you have issues setting it up, you can ask here. We will be able to help you get it set up.
I don't have a smart tv so I cannot answer your other questions.
I just looked at your post again. If you get a router you will be able to set the TV up to the network you created and leave the computer as it is hooked up to the modem. You may need to refer to the TV users manual when you get ready to set it up.
Edited by Queen-Evie, 25 July 2014 - 12:36 AM.