Can I be a lesbian and still have a crush on a guy?

Well, there's a few labels like bi lesbian which could include both if that's easier for you, especially if you only have sexual attraction to men but not romantic or vice versa and you feel that effects your identity. But labels are for you to be able to describe your experiences and identity to other's so you should choose what feels most comfortable for you and what you think is going to get the point across best to the people around you. For example I'm bisexual but I'm only interested in masculine people and I vastly prefer men or masc leaning non binary people and I'm also Aromantic and in a committed relationship with another man so it's unlikely I will ever be in anything but a gay relationship. I chose these labels because the describe my full identity in a comfortable way but at the same time a lot of my family and non LGBT+ friends find the rest of my identity to be too confusing and I personally don't want to be in that situation. I don't even know how I would TRY to explain that to my grandparents. But I know they'd be accepting and I don't particularly feel like I need to tell everyone I know, including some of those who I'm immensely close with, the intricacies of my sexuality especially when it does not effect them in anyway so I've told them that I am gay, since I am functionally gay, and that's the only thing they've needed to know. To be clear there definitely should be emphasis on me being comfortable with this arrangement, this isn't what's comfortable for everyone and you may feel more comfortable selecting the more comfortable label or a micro label you feel fits best, it's up to you.