Ariel Winter -- I'm Going to School ... For the First Time!!

Ariel Winter's about to do something she's never done before -- attend high school like a normal kid, and get this ... she can't wait to go ... TMZ has learned.

The "Modern Family" star is now enrolled in a private school in the L.A. area and will start attending classes later this month ... sources familiar with the situation tell TMZ.

It's a big change for Ariel because we're told she's always been privately tutored.

According to our sources, producers at "Modern Family" are "thrilled" and will happily schedule shoots around the girl's classes.

We're told Ariel has been "flourishing" in her sister Shanelle Gray's home, where the rules are strict. Sources say Ariel's happier than ever, and producers have noticed a big, positive change in her mood.

As we previously reported ... Shanelle became Ariel's temporary guardian after allegations surfaced that her mother, Chrystal Workman, was emotionally abusing her.

Ariel's attorney and father now have control over her considerable finances -- $75,000/episode -- as per a settlement hammered out last month.

We've got 2 words for Ariel: cafeteria lunches.