You didn’t provide much background.
I don’t know if the preprogrammed channels will survive a reset. Your seller can advise you. What I would suggest is to download the configuration from the radio before performing a reset.
As far as your second question, whether CTCSS should be on, it depends on whether whatever radio you’re transmitting to is set to expect CTCSS. If you’re just transmitting in hopes that someone will hear you and chat with you, then leave CTCSS off. If you’re trying to get into a repeater that requires CTCSS, then turn it on, but you must make sure to set the right CTCSS tone to transmit.
When getting started it’s usually better to leave CTCSS off on the receive side, at least until you know what you’re doing.