Acceptable times for first marathon?

Hey guys,

I am hoping to run a marathon this year, but I want to run a slow one. Is it acceptable to run a 5 hour marathon? Should I aim for quicker?

Edit: Thank you everyone for the advice!!! For reference, I am currently a 22 year old female who lifts a couple of days a week, and does some inclined walking/jogging for cardio. Everyone had great advice; I think I will do what the majority of you said and start it just to finish it, and use my first marathon as a baseline. I appreciate everyone who took the time to comment!!! This group seems INCREDIBLY supportive