It depends…liking the way guys look but not imagining them in a romantic/and-or sexual way could just mean you think they’re nice looking, similarly to how you think one of your friends is pretty but you’re not attracted to them. If the way you think a guy looks good feels the same way as it does for someone you KNOW you’re not attracted to…then you’re probably not into guys.
Also if you DID have any attraction to guys, but it was so low or insignificant that you had no desire to act upon it, and felt it didn’t really define who you wanted to date etc, you don’t have to label yourself bi if it doesn’t feel right. If girls are all you’re interested in being with in any capacity, it’s perfectly okay to just define your orientation by that.
Also! You don’t just need to focus on guys. If you’ve ever thought about the possibility of dating non-binary people, wanted to date someone who was, or felt some kind of attraction towards someone who was non-binary, you’re allowed to call yourself bi too, whether you like guys or not.
Orientations are really difficult to work out! It’s often best to try and go by whichever label you seem to gravitate towards. If you try on a label like “bi” and it feels right, like it fits. If it feels comfortable. Then you don’t NEED to be 100% certain to use it. But if “gay” or “lesbian” feels right to you, that’s also perfectly fine. You don’t need to be 100% certain. You’re allowed to get things wrong, you’re allowed to try identities out and see if they work for you. Take your time.
Another thing is, if you’re questioning or unsure and don’t want to label yourself gay or bi yet…you know you’re a girl attracted to girls. You can always define yourself by “sapphic” or “wlw” or “girls who like girls” if you’re unsure or if you prefer. There’s also the option of “queer” if you feel comfortable with that.
About the gravitating thing, something that helped me was, for example, think of gay and bi celebrities. I felt a real affinity/strong connection towards celebrities who identified as bi, moreso than I did for celebrites who identified as gay. That helped me to figure out my identity, working out why I felt such a connection towards one group over another.