Also some of my already saved documents do not show correctly. Letters are very very small and not readable! I can not bring anything in the normal size.
Hello,
Although not definitive using the word “some”, it’s possible the zoom factor was changed. Please see answer in this post.
Hi, Elenita!
In relation to the problem (“I can not bring anything in the normal size”): have you tried the zoom function?
To zoom in/out on a Mac it’s while holding down command, use the mouse wheel.
I don’t own a windows computer, but since the windows equivalent of the Command key is the Windows key, I assume the process is while holding down the windows key, use the mouse wheel.
If you have a windows computer and that doesn’t work, try holding down the other keys individually (Ctrl/Alt) and scrolling with the mouse wheel.
Please let me know if that answered that section of your question.
Also, please ask questions individually (there are three questions here:
• The first is related to “everything being small in a new document”,
• The second is “some of my already saved documents do not show correctly. Letters are very very small and not
readable”,
• Finally the third is “not being able to bring anything into the normal size”.
Asking questions separately/keeping the question description relevant to the title will likely lead to faster answering of your questions, as those who see the title may know how to answer the question in the title, but not the additional question(s) in the description below the title.
In addition, users who see your question’s title, realize that they know the answer, click into it and answer it
but don’t know the answer to the other question(s) in the description will get the karma points they deserve (users gain karma points when their answers are accepted via the tick to the right of this text box) in return for answering your question, when you accept their answer.
Cheers 
@appreciatethehelp The ‘Ctrl’ (Win & Linux) key is the equivalent to the ‘Command’ key. You’ll find this in almost every chapter of the LO documentation.
Thanks. And yes I have a desktop pc with windows 10. Before I received your answer, I tried something even easier Turn fonds to Times New Roman 78 !!! So everything is huge… Thanks anyway
Sorry guys, I didn’t realize the windows equivalent keys are different in LO compared with using them outside of it.
I got the list of equivalent keys from here:
Windows Keyboard Equivalents for the Mac's Special Keys.
Glad you found something that worked though!