This is a very common question that I would get from other undergraduate students.
First and foremost, I want to let everyone know this: Regardless of your experience and class level, it is not impossible for you to get into a research lab.
From my experiences and from what most underclassmen…
Also keep in mind: many professors want undergraduates that they can mentor. Don’t assume that you are the only person who will be getting something out of this! If you show a willingness to learn, there are professors (such as my mentor) who enjoy showing people what research and academia is all about, not only because it expands their network if you decide to pursue academia but also because they’re passionate about their work and they want other people to be passionate about it, too.
I started working in a lab three years ago after I went to my advisor in the Ecology department and asked him who I could work with. He directed me to one professor, who pointed me towards a second professor, who pointed me towards the professor that I eventually ended up working with. I’ve done two of my own research projects with her, written a paper that will be published this year (hopefully, assuming I get off Tumblr long enough to write it…), and a graduate student in her lab pointed me towards an REU and I ended up working in New Mexico last summer because of it.
tl;dr, don’t be afraid and start asking around!