what to do regarding transmission?

i’ve had my car for about 6 years and i’ve never changed the transmission fluid. stupid, i know. anyways, it has 117,510 miles on it. 2017 honda civic ex sedan. would it be better just to get a new car since i did not take good care of this one or put money into trying to fit it?

there is a kickback that happens while driving that has been going on for a few weeks. the check engine light is on saying “emission system failure”.

kinda overwhelmed and unsure of what to do next. any help would be great!