wondering if there are any tags features
There are several. What kind of tags are you looking for?
Most (e.g. metadata fields for music files, and generic tags and comments/descriptions) can be accessed via the metadata pane (Lister > Metadata Pane, or the toolbar button for it, or F9 hotkey).
There are also labels (usually used to color files/folders).
I want to tag some important documents and folders so it would be easy for me to search / list them later when I need. More of easy accessibility.
Using labels probably makes the most sense for that:
https://www.gpsoft.com.au/help/opus12/index.html#!Documents/Labels1.htm
Note that if the labels are stored in NTFS, they can be lost when editing files with some software, if the software deletes the old file and creates a new one in its place without transfering the old metadata over.
You can store labels in the config file instead, if that's a problem with the software you're using, although that will also mean the labels don't move with files/folders when you move or rename them.
You can search for files with labels using Tools > Find Files > Advanced.
Thank you. Will explore more on this.