How to easily switch from cable to where the streaming apps are located.

I'm helping an elderly friend with her TV. She's had a Uverse cable package for many years and never used any streaming services. Now we'd like to give her access to some streaming apps, but we're having trouble easily exiting cable to the screen the apps are on, and then back to cable.

It's probably very easy, but I just use a smart TV with no cable package added, so this is unfamiliar.

The cable channels come up when she turns the TV on, instead of a Home Screen of any kind.

She'll use the streaming if we can make moving between her beloved cable and the apps easy. If it takes more than a couple of steps, she won't do it.

If anyone has advice I'd appreciate it.

I called/chatted with ATT and didn't really get any help. They didn't seem to understand what I was asking.