Pleco is a dictionary with some other capabilities. It doesn’t teach grammar nor sentence structure, nor other language functions.
It can HELP with those, but it’s primarily a dictionary resource.
Which books are better “teaching” you Chinese depends on what you want to spend.
IMO, the Integrated Chinese V4 series is much better than the other book series IF American English is your mother tongue. However, they are “college textbooks” and come with the hefty “college textbook price”.
The HSK series of books and New Practical Chinese Reader are all published by mainland Chinese authors, where they tend to believe putting example Chinese sentences with no English translation is helpful, but which I find extremely frustrating.
There are many others, but these are the ones I have direct experience with.
I would suggest hopping on italki or some other similar language-learning website and finding a good teacher to work through whatever books you choose.
edit: and as a grammar encyclopedia, by far my favorite is: Modern Mandarin Chinese Grammar: A Practical Guide (Modern Grammars) 2nd Edition, by Claudia Ross and Jing-heng Sheng Ma. No matter how many grammar books I have, this one is where I always find the best answers. However, it is a REFERENCE book, not an instructional book. It’s technically dense, but fantastic for looking up grammar points and issues.