cannot save document

hi, i can't seem to save after editing. referring to a previous forum post, i followed the instructions to help save but i still can't seem to.

maybe i'm not used to the format of zoho writer. but when i type, a strange dotted border surrounds the body of my text and sometimes it splits into different rows according to how the text is written. and if i type outside of this border, nothing gets saved. even if i write within the border, changes i make still don't get saved.
this phenomenon is regardless of whether collaborate editing is ongoing or not. why is this so?

also, anything i write within the border is unable to have different formats. for example, if i center-align a row of words, the row(s) of words below that first row follows suit. how do i correct this and prevent it from happening?

is there by any chance, an online manual to use zoho writer?

please help, thanks.