Learn French: Nous sommes en avance.

In French, tôt means early in the day (like waking up at 5 AM). En avance specifically means early for a scheduled time, meeting, or appointment. Because this sentence is about being ahead of schedule, you use en avance.

Since nous (we) is plural, why doesn't avance have an "s" at the end?

En avance is a fixed phrase that literally translates to "in advance." It is not an adjective, so it never changes its spelling to match the subject. It stays exactly the same whether you are talking about one person or a group.

Since this lesson is about the verb venir (to come), how would I say "We come early"?

You can simply swap out the verb! Using the "we" form of venir, you would replace sommes with venons to say Nous venons en avance (We come early / We are coming early).

How do you pronounce en avance together?

Because en is followed by a word starting with a vowel (avance), you make a liaison (linking sound). The n sound from en slides directly into the beginning of avance, making it sound smoothly like en-navance.