Couple of questions before I start first ever grow

Hey there,

I've finished reading the beginners guide and I'm about to begin my first grow, but before I begin, I have a couple of questions that I don't recall being answered in the book.

1) The PH and TDS tester were labelled as optional, so I didn't buy them, but the latter chapters seem to heavily rely on the checking of PH & PPM levels. How do I navigate knowing when and how much liquid nutrients, PH adjusting, flushing to do, without those instruments?

2) How often should I have the oscillating fan on for at any time during the different grow phases to ensure air circulation, but not wind burn etc?

I'm also thinking about logging the process of the grow with notes, was wondering if anyone can suggests things I should be monitoring to log or if there's a spreadsheet or something like a site, software/app etc for logging grow progress.

Thanks in advance to everyone that responds