I have started LO Database and now I have a lot of questions. Recommend me please some LO Database Guide or Manual. Windows 10, LO 184.108.40.206
We are not going to have a Base Guide 6.3. But you can use Base Guide 6.2 (see my answer) as not much has changed from Base 6.2 to 6.3.
This page has much of what you need:
The Base v6.2 manual (translated from German) is the most recent. But not a lot has changed in many years.
If you want more, see this post for links → To learn LibreOffice Base are there introductions or tutorials?
You can download the Base Guide 6.2 from https://wiki.documentfoundation.org/images/b/bf/BG62-BaseGuide.pdf
The Base Guide 6.4 will be released by the end of June 2020.