General help

I am a new user of Moodle for School (3.6.4 School). There are couple of questions that I need clarifying/help with.

1. Why doesn't the text/content box not showing the font selection.
2. why doesn't the calendar and the blocks change to the customized color
3. why won't the assignment resource show me the submit button
4. why won't my file picker accept my PDFs all of the sudden

I would greatly appreciate if the reply will be in detail. Thank you.