Hey there Katie,
Welcome to planDisney and thank you for your question! As a fellow parent of small kiddos, I understand the importance of needing to get a basic schedule prepared for a visit to the Happiest Place on Earth. With so much going on (and potentially cranky little ones) it's good to go in with a plan!
The resource I typically utilize when thinking through the details of my upcoming trips is the
Hours & Events Calendar. It looks like you noted an arrival date of Feb 14, so if you select the "Change Date" link near the top left of that page and select your date, it will show you all your entertainment options and park hours for that date.
For the 14th, I'm seeing that currently Disneyland Park's hours are 8:00 AM to 11:00 PM (though I'll note it's always possible these hours and entertainment times are subject to change depending on unforeseen factors like weather, etc). That evening,
Fantasmic! is currently scheduled for 9:00 PM and 10:30 PM and
Wondrous Journeys with Fireworks is scheduled for 9:30 PM.
I also wanted to note that
Paint the Night, an amazing night time parade, is scheduled for 8:30 PM as well.
If you and your kiddo love the nighttime entertainment, I would recommend trying to catch all three! You could set up in front of
Sleeping Beauty Castle to catch Paint the Night, then head over to the Rivers of America (near the
Mark Twain Riverboat dock) for Fantasmic! and back out to Sleeping Beauty Castle for the fireworks.
Admittedly, those are quick turn around times, so depending on your mobility, it might be worth just catching Fantasmic! followed by Wondrous Journeys after like you originally mentioned, but I love a good stretch goal! Either way, you have lots of really phenomenal options to make it a magical night.
Thanks again for your question, Katie! I hope you have an amazing time.
Have a Magical Day,
Greg