How can I save all my passwords without a password software/manager?

You can use a technology which is software independent. All you need is to remember ONE masterpassword. The working passwords can be written on paper and kept openly. See more https://bizpages.org/en/safer-password 

The most secure is to not have them on your computer.  Password saving programs can be hacked and text is easy to search on your computer by any hacker - but if you write them in a graphic and not in text then when saved to your computer they are not text searchable.  My husbands a computer programmer I save all my passwords on my computer in a picture graphic and not in text.  Only someone who knows the name I use for my password graphic could find it on my computer and of course I don't name it with "pass****" or anything like that.

Get a notebook and write them down. Keep it in a closed place. Don't tell anyone where it is. Pretty simple, eh?  

In a little black book.  Write them down and keep the book in a safe place.

This is very important when you get older.  The Executor of your estate will need to know your login details.

save them in text files and create a folder for them

in the fat that's between your ears

in microsoft edge you can , but thats only web sites , for office try a freeware site .

You can write down the password in a notebook or remember it on a browser.

Your head.  You can also write them down in a small notebook. 

Write them on a piece of paper and put it in between some books.