For the absolutely absolutest absolute beginner readers whose first read will be Chi’s Sweet Home, remember, the first chapter (of whichever manga you start with) is always the hardest. The second chapter is going to be the second hardest. Not quite as hard as the first, but still pretty brutal. The third chapter, as it turns out, is going to be the third hardest. It might even feel like the first or second hardest as you’re still getting used to everything.
The associated vocabulary spreadsheet will assist with words you don’t know, as well as words spoken in a babyish voice (notably from the kitten, Chi). However, this doesn’t help out at all with grammar. Even if you know all the words in a sentence, it may still be unintelligible until you know the grammar. Be sure to either look up grammar you don’t know, or ask in the weekly chapter threads, and chances are you’ll get a response giving a breakdown of the grammar involved.
In my earliest reading attempts (Sailor V, back before it has an official English release), I failed to make progress because there were too many vocabulary words I didn’t know.
Fast-forward to the proliferation of SRS flash card software and my learning many more vocabulary words, my second attempt was with a different series (Yotsuba&!), and this time I failed to make progress because there was too much grammar I didn’t know.
Both times, I let my progress stagnate rather than learning what I needed to and moving forward.
Finally, much more recently, I picked a comic (Is the order a rabbit?) that not only had a lot of words and grammar I didn’t know, but also lacked furigana readings on kanji, and this time I forced myself to read through one four-panel strip per day, looking up every kanji, and looking up every vocabulary word I didn’t know, and (as best I could) looking up and learning every bit of grammar I didn’t know. This has lead to an increase in vocabulary and the amount of grammar I’m familiar with.
This will be your first step down one of the many roads to learning Japanese. If possible, stick with it no matter what a little kitten throws at you!