I'd like to hide some of the metadata (author, date etc...) from the posts
In order to remove all the metadata of the posts, please use the following css under custom css box at the customizer:
.entry-meta {display:none;}
If you want to delete only the Publish date, try this:
.entry-date {display:none;}
If you want to delete only the Reading time, try this:
.reading-time {display:none;}