Hello Juanjo,
Thank you so much for using support forum for the query.
1. Please check all the available options on every widgets.
2. Check all the available options on Appearance > Customize > Layout/Design Options > Blog/Archive Options and find the options there.
3. If the above steps will not help to hide or remove the date and author, please add the below css codes on Appearance > Customize > Additional CSS
.entry-meta {
display: none;
}Hope, this will solve your problem.
Regards
Acme Supports