What Viking OSX said, plus a few comments.
"is it possible to upper case 1st to 9th automatically (for example 1ˢᵗ to 9ᵗʰ) in Pages on a MacBook Pro?"
"Upper case" and "lower case" are terms that originated in the days of hand setting using foundary type (individual letters and numerals, plus some spacing blocks or strip. After a hand set document was printed, the page forms were deconstructed and the type blocks were stored to be re-used on future jobs. storage of each set of foundry cast blocks were placed in two cases; an Upper Case to hold the UPPER CASE characters, and a Lower Case to hold the 'lower case' letters.
Although hand set type is rare these days, the terms still refer to CAPITAL letters as Upper Case and 'small' letters as Lower Case.
The term for the type you are describing is "superscript"—text that is placed in a position that is higher than (superior to) the baseline of regular text.
As for producing superscript text in a Pages document, the simplest current method is what Viking has suggested—a set of text replacement strings that will automatically replace individual 'key' strings entered into a document.
As text replacement is automatic (and universal), you will need to choose a key string that will not occur normally in locations where you do not want the superscript text to appear.
"It's more common in the English language and so it should be available."
Things that should be available in Apple Software (or Hardware) are beyond the scope of these user-to-user communities.
Use the Provide Pages Feedback menu item in the Pages menu to send a Feature Request directly to Apple.
Regards,
Barry