Well, usually in the story, kids might first put on their school uniforms. That's a very common step. Then they would pack their school bags with books, notebooks and pens.
In a fanfiction scenario, perhaps Plankton frames SpongeBob for stealing the Krabby Patty secret formula, which gets him fired. SpongeBob then goes on an adventure to clear his name. Along the way, he meets new friends in other parts of the ocean who help him prove his innocence and he returns to the Krusty Krab triumphant.
Mr. Krabs would probably be thinking about how this could be good for business. He might see it as an opportunity to create a new tourist attraction. Patrick would be really happy for Spongebob at first, but then he might get a bit jealous because he doesn't want to lose his best friend. Squidward would be extremely annoyed by all the commotion and the fact that he has to be part of the wedding in some way.
In a Spongebob gets hurt fanfiction, it could start with Spongebob being overly excited as always. He might be chasing a jellyfish near the dangerous cliffs. As he dashes around, he doesn't notice a sharp rock. He trips and falls right onto it, cutting his sponge body. His friends, Patrick and Sandy, hear his cries. Patrick, being a bit clueless, just stands there while Sandy quickly runs to Spongebob's side. She uses her karate skills to break off a part of a nearby tree to make a splint for Spongebob's injured part. Spongebob is in pain but also very grateful for Sandy's help.
It might also be that Spongebob has made a series of small mistakes that have piled up over time. In the fan fiction, he could keep forgetting to do simple things like his job at the Krusty Krab properly, or he's always late for important meetings. This cumulative effect of his carelessness could lead to everyone getting frustrated and mad at him.
Often the main characters are students. For example, a boy named Tom who is a bit lazy in the morning when getting ready for school. His mother always has to remind him to do things like tie his shoelaces.
It could end with the family realizing the enormity of their actions and stopping before it's too late. Maybe one family member has a change of heart and convinces the others that lynching is not the way.
It could be really cute. They might have an underwater and land combined wedding. Spongebob would bring all his Bikini Bottom friends, and Sandy would have her treedome pals there. Maybe Mr. Krabs would be in charge of the 'food' which would be a mix of sea - food and acorns for Sandy. And Squidward would be reluctantly playing the clarinet at the ceremony.
Well, it's all about SpongeBob's various mishaps and funny attempts during the license test. His overenthusiasm and lack of certain skills keep getting in the way.
The most important aspect is probably the spiritual or religious significance. You need to convey your character's understanding and respect for it. For instance, if there are specific chants or hymns, your character should know them. Another aspect is the social aspect. In a liturgy, there are often other people present. How does your character interact with them? Are they part of a community? And of course, the physical preparation like wearing the right attire and having any necessary items.