So I've recently upgraded my wardrobe and started working out, and I've been noticing a lot of girls smile and try to make eye contact with me - especially when I am walking between classes. Time between classes is quite short and people are usually in a hurry (and it is sort of crowded). With that in mind, what can I do after receiving a smile/some eye contact as I walk by these girls?

I am very new to the red pill, and I'd also like to mention that I go to a very small liberal arts college (class size ~500) so one of my fears of approaching girls is that I will definitely run into them again around campus. Any advice about this?