Restore from backup?

Short Answer: No

It depends on the changes made as they all have different rollback mechanisms.

e.g. If you made a change to a page or post – you can use revisions to back back.
If you changed the settings of a plugin – there is no history or roll back.
Appearance Menu edits – no roll back

However, if you do have a backup – you can replace the database and all the files and it will go back to the previous state

OW, sh**!
OK! Then I have to do it the hard way… I have now 4 problems. Let′s see, who can help me with what. First of all, sorry for my bad English.
Second, I use Custom Community theme. Third: theme, plugins and wordpress itself were upgraded to the newest version yesterday.
Now for the problems. I have currently 4 of them. I′ll write how it was before and now. I would like to change everything to how it was before.

1. Background. I have my own background image.
before: Image was static. That means, when you scroll the page, the background won′t move an inch.
now: background moves with the page and repeat itself

2. Headbanner. I have my own there. On the top of my page I have the top menu. That is not affected by scrolling and is always there. That is OK. Right under it is the main banner
before: Banner started right under the top menu
now: the main menu covers a part of the main banner

3. A problem with link in tablepress. The color schematic of my whole web is dark, text is white.
Now: Problem is, when I go with mouse to a row, that contains a link to another web. the row has bright color.
Before: No affects on color, brightness or marking or anything.

4. Big problem with combo tablepress / images. The main table I use contains images. Normally they are small, about 60×80 or so. When you go with mouse on an image, it grows to full size. A similar effect, as on this web: https://anidb.net/perl-bin/animedb.pl?type.tvseries=1&show=animelist&orderby.name=0.1&noalias=1&do.update=update&airdate1=1.12.2016&airdate0=10.9.2016
I use this kind of command direct in tablepress cell:
<div id=”animecover”><img src=”https://i2.wp.com/(webpage)/wp-content/uploads/24831.jpg&#8221; />
and now: all images are at full size the whole time

Problem No. 3 solved. The rest is still open

1.

background-repeat: no-repeat; // don't repeat down the page
    background-attachment: fixed; // don't scroll
    background-size: contain; //make the background fit in the area: https://www.w3schools.com/cssref/css3_pr_background-size.asp

2.
This is never easy to fix but you can use the following:

background-position: center 100px; //centered with a 100px margin at top

4. You are using the fuull size image – you need to get the URL of the smaller image. Because you are hard coding, you need to find the alternate URL.

Thanks, Shannon W, but… stupid question… where shoul I put that command from points 1 and 2?
About No.4 – I never had URL of the small images, because those images never existed in small size in the first place.