Importers are broken right now I think.

For passwords, goto the URL chrome://password-manager/settings in both Chrome and Opera. In Chrome, click "Download file" to export your passwords to a CSV file and in Opera, click "Select file" to import that CSV file.

For bookmarks, in Chrome, goto the URL chrome://bookmarks and click the 3 dots at the top right to export your bookmarks to an HTML file. Then, in Opera, goto the URL opera://settings/importData, click "Bookmarks HTML file" in the drop-down and point it to the HTML file to import your bookmarks. Then, goto the URL opera://bookmarks and move the imported bookmarks to where you want them.

If you need to copy opened tabs over from Chrome, right-click on an empty spot on the tab bar and choose "bookmark all tabs" before you export your bookmarks. Then, in Opera, you can right-click that tabs folder and choose "open all in tabs".