I wanted to look at the items I have in my save files, trying to find my potions and ingredients. However, I cant find them anywhere. Where do I locate those?

The folder for saves has an address resembling C:\Users\USERNAME\AppData\Roaming\Strive\saves on Windows.  The easy way to access the folder is to start the game, start/load a progress, then go to the Save/Load screen and press the "Open folder" button.  They are text/JSON files so any text editor will work.

Edit: The Windows way is to open a file explorer, put "%appdata%" in the address bar, and press "enter" if needed. Find "Strive" and then "saves".

Items can be located by searching the file for "itemlist or "backpack".  More info about items can be found by opening items.gd(also a text file), which is found in the Strive application files.