confused about number of tvs allowed

DTV is a satellite service with a dish and DTV receivers and there is a $7 fee for each TV, you don't pay for a modem.  New customers are under a 2 yr contract that is reduced $20 per month so you pay for unused months left if you cancel.  Geek squad AFAIK  doesn't install DTV.

Geek Squad is out of Best Buy, a 3rd party retailer, not DirecTV itself. So be cautious of any offers or information there.

DirecTV is a TV service, not internet, so doesn't have a modem.

You pay $7 for each additional TV on the service not matter what kind of DirecTV receiver or client you use.

When you start DirecTV, or do an upgrade of equipment (adding another TV counts), it comes with a 24 month agreement. That agreement is valued at $20 for each month remaining. So if you cancel service, then yest you pay an early cancellation fee (ECF) based on how many months you had left.

However, if by "change service" you meant making changes to your existing service (upgrading equipment, changing programming, etc.) that does not require you to cancel and start a new account as you are not locked into keep the exact setup for the length of your agreement. The only requirement is you keep DirecTV itself.

To see what you have, log into your DirecTV account or call DirecTV. Geek Squad doesn't manage your account so shouldn't have a clue what you have unless you tell them.