Hello Ariel_D,
We see you're looking to reopen closed tabs in Safari, and we can help to get that cleared up.
For normal, non-Private tabs, you can use the Safari menu at the top of the Mac screen, select History, and choose Reopen Last Closed Tab. If you're using iOS, this would be done by long pressing on the '+' button in the tabs window.
Closed private tabs may not have an option to be re-opened.
If you're experiencing your tabs being closed automatically on iOS, try checking in Settings > Safari > Close Tabs, as this option would automatically close them after the set time period.
Cheers.