Different questions, but definitely linked and related to one another. In short, yeah, most people don't start to gain confidence in their work until they've produced quite a lot of pages. As @darthmongoose was getting at, it's simply a matter of practice, study, and eventual "mastery" (or at least competence lol). Even if you're an amazing artist or amazing story teller, marrying the two together and attempting to create an amazing comic is hard! And harder so if you're only so-so at either side haha.
For a personal anecdote, I just completed my first comic over the course of 2018-2019, ended up producing a 70 page comic in about the span of a year (October - December, 14 months). And... at the end of that? I still feel pretty iffy with how a lot of the pages came out haha. Like, I absolutely improved a lot and feel a lot better about the later pages than the earlier ones, but even at that # of pages in I still feel like I have a long ways to go. And that's not to mention countless comic projects that I've done in the past which technically qualifies as experience- several 1-10 page comics that didn't go anywhere probably add up to easily 60+ other pages on top of that xD
So, tl;dr. yes that's pretty normal to still be feeling that way at page 11. And although everyone's different, it's best to prepare to still possibly be feeling that way at page 100 too tbh haha.