So I finally bit the bullet and bought a Canon 90D because I really want to get into photography properly instead of just using my phone for everything. I am so excited about it but honestly Im completely overwhelmed by all the lens choices out there. Like, I went to the camera shop downtown and the guy started talking about f-stops and focal lengths and my brain just kinda shut off. I feel like a total idiot asking this, but what is actually the best all-around lens to keep on the camera most of the time?

Im heading to Italy in about three months and I really want to be able to capture everything from big landscapes to maybe some street shots without having to carry a giant bag of gear. My budget is probably around 600 or 700 bucks maybe a little more if it is really worth it. I was thinking maybe I should just get one of those super zoom lenses that does everything but then someone online said they are bad? I dont know. My logic was if I get one lens that covers wide stuff and zoomed in stuff then I dont have to worry about changing lenses in the middle of a crowd or somewhere dusty.

Is there something that isnt too heavy? I want to be able to walk around all day without my neck hurting. I looked at the 18-135mm kit lens thing but wasnt sure if it was 'good enough' for the 90D or if Im going to be disappointed with the quality once I get home and look at the photos on my computer. Maybe there is something better that isnt crazy expensive? Im so lost with all these acronyms like IS and USM and STM, I dont even know what I should be prioritizing. Should I just stick to the kit lens or is there a holy grail lens that isnt going to break the bank for a beginner like me?