We selected an afternoon showtime.

There were many families to watchwho came to watch the movie.

"There were many families to watch." is a bit ambiguous and can mean that you are watching the families there.

The movie was very fun.

Usually fun is used for an event or an activity. For example, "the movie date was fun!"
For the movie itself, it is better to describe as interesting or enjoyable.

I wondered why Nick and Judy didn’t have romantic relationships..

If you are referring to they didn't get together at the end, relationship should be singular since you are referring "the relationship" between them.
If you say relationships, it meant they each did not have a relationship with someone at the end.

I am pretty sure that they liked each other!

We selectedchose an afternoon timeshow.

There were mMany families to watchhad come to watch the movie.

I know it i's a kids' movie, but I am a fan of Disney, so I didn’t want to miss it!

The movie was verreally fun.!

Alternative: "I really enjoyed the movie!"

In the last sceneDuring the climax, I almost cried.

The climax, although not necessarily the last scene, is the turning point in a movie.

I wondered why Nick and Judy didn’t have a romantic relationships..

I am pretty sure that they like each other!

Zootopia 2

There should be a space between "Zooptopia" and "2".

My husband and I watched Zootopia 2 today.

We selected an afternoon showtime.

When talking about watching a movie in a theater, you can use "showtime" to say when you watched it.

There were many families there to watch it.

I wondered why Nick and Judy didn’t haveend up having a romantic relationships...

If you are still wondering about this, "wonder" fits better. If you only wondered about this for a bit after watching, "wondered" works.

I am pretty sure that they like each other!

You can either keep or remove "that", both options work.