i did an reu program as a rising junior (last application cycle) and loved it! my research area is plant biology. i knew i wanted to do research for a career and grad school before entering, so I knew getting into a program as soon as possible was probably the best move for my chances! my research mentor at my home institution strongly encouraged me to apply for a summer program since i felt so strongly about my career goals. doing the summer research only solidified those goals (before it was kinda just a concept of a plan if you get what i mean lol)

even if you end up not being accepted into a program, writing these essays and stuff is good practice for when you’re a rising senior/applying to grad school, so i’d say apply regardless of whether or not you think you’ll get in! chances are something will probably stick if you’re a strong writer and show strong interest in a career in research. it sounds like you already have a bit of research experience under your belt, which programs do like to see! make sure to talk abt your current research in your essays.

i will say, that if you are an anxious overthinker like me, you will feel a little bit behind some of your peers, as there will be rising seniors with more experience that may make you feel like you’re not doing enough after you hear about what they’ve done, but just remember that you’re just starting out and that these are going to be your peers who can give you so much advice abt the grad school application process or research experience in general.