I am new to TYPO3 and have a big problem. I deleted the page with the id 1 (startpage, I know its stupid) and now I woudl like to know if it is possible to restore the page somehow.
['https://Stackoverflow.com/questions/40584664', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/3649851/']
Install extension Recycler, it ships with TYPO3 by default. You can then restore pages and content you deleted using the backend UI it has.

<https://docs.typo3.org/typo3cms/extensions/recycler/Introduction/Index.html>
You can use the recycler that is found under the web module and click on a page in the page tree at a higher level than the deleted page. You can also set the depth to infinitive if not certain where the page used to be in the page tree. Then put a tick beside the page you want to restore and click undelete. Note that PID is 'Parent ID' (not Page ID), and UID is the ID of the deleted page.If you click on the little + you will get additional information, e.g. the original path to the deleted page. If part of the path is highlighted in red, then that indicates another deleted branch or page. Remember to leave the Recycler module with 'Depth' NOT set to 'Infinite' (leave it at 'This page' or '1-4 levels') otherwise the recycler will hang if you use it on a larger part of your page t ree. Hope this will help you.