When opening an item, any
BEGIN_QUOTE ... END_QUOTE blocks are automatically expanded. Is there any way to keep them collapse, and only expand if I consciously TAB on that block?
There are in buffer settings for many things like this in org -> https://orgmode.org/manual/In_002dbuffer-settings.html For code blocks specifically there are these startup options:
To hide blocks on startup, use these keywords. The corresponding variable is org-hide-block-startup.
hideblocks Hide all begin/end blocks on startup nohideblocks Do not hide blocks on startup
If you want that to happen globally just set that variable to true in your config file:
(setq org-hide-block-startup t)