Anyone can edit all pages*1. You can edit page after clicking edit(編集 henshu) link. Contents are formatted according to Formatting Rule.
No problem occurs if you treat the Page for practice whatever you do. Let's practice editing there without care.
Viewing in some existing page, Click edit(編集 henshu) link, and then input WikiName(name mixed with upper and lower case) or BracketName(enclosed with [[]]) and save. After that you find ? link following after your input. Click that link and PukiWiki opens new text area ready to edit. You can write in the area in the same way as modifying other pages.
3m means 3 minutes ago around, 5h 5 hours ago, 8d 8days ago.
Yes, it is not apparent who modifies that page.
If you are annoyed, write your name after you writing, like this:
--foobar
Yes. It is WikiClone?'s nature. Anyone can write, erase and even spam. But it is in vain, for PukiWiki has the function of regular backup. We can recover the writings, though not perfectly.
While you are editing the page, someone might edit the same page. Then what will happen? Be at ease. PukiWiki compares the update time of original and updated document.
If the timestamp differs, it is "collision of updating". In that case, reload the page to update and edit again.