Senor-Sudafed's journey

I'm currently working full-time in animal care, but I'm considering quitting because the work environment isn't what I expected. I've only been there for a few days and it's been quite disappointing. My concern is that quitting might negatively impact my future job search. I've heard that it's generally easier to find a new job while you're still employed. I also have a part-time job in guest services that I've held since August, which I would keep if I decide to leave the animal care position. I'm wondering if having a part-time role would look less impressive on my resume. I've read that hiring managers typically focus on job titles, employers, and dates rather than whether a position was part-time or full-time, so I'm hoping that staying employed in guest services would actually strengthen my position while I search for something better.