Best ratings in the us navy with good quality life and off base housing, Information Warfare/ CT field question and undesignated

Hey all. I've been looking into join the navy for a while. I'm mid-late 20's (27) and I don't think it's too late yet. I got a degree in Biology but I don't think it means much. Right now I'm looking at the Information Warfare field as a Intel specialist or a field in the CT community, particularly CTN or CTI, which has recently been changed into "CWT". It's either that or CTI. I know CTI requires a specific score in the line scores and a dlab score to join I think. And compared to the other CT rates, which CT rates would you recommend and for the other ratings? .

I'm also looking at Intel. Does anyone know if CTN/CWT, CTI, and intel ratings are on shore mostly but there's a possibility to be on ship assignments? I don't mind but I'm wondering for those people in CT field, particularly, CTN/CWT and intel navy folks out there how do you like it so far and are you on shore or ship duty?

For those "Information Systems Technician" do you guys work on ships or on shore?

Lastly, why do people end up going undesignated or something? I'm guessing they do a poor job on the asvab so they don't have any job openings, and/or failed a-school for their rating and end up undesignated. Is undesignated a permanent thing and what's it like? And is it good or bad?
If not CT, what are some good ratings? I hear LS is also good and retail specialist, I've worked long enough at retail and logistics/warehouse too long that I want to try something new.