Here are the locations of the 1-ups: {On the Mario Starship

There is a CHANCE DICE on your ship. Spin it and if it lands on a 1-up, it will transform into a 1-up.

Once you have Yoshi on your ship, use him to fly up the flowers and eat all the fruit. You will get 1 1-up.

Once you have access to the TOAD BRIGADE, fly to their ship and they have a 1-up aboard.

As you progress through the game a pipe might appear in Marios ear. Go in it to find 2 Luma. One gives you 1 chance cube for 30 Starbits. The other charges 30 coins for 5 spins.

Once you have a Cloud Flower on your ship there is a secret cloud above your ship that has a 1-up on it.

Other:

After completing a level and your new total coin count is over 100 you will get a 1-up

In a level if you get 100 Starbits you will get a 1-up ---skyp