Family is also a theme sometimes. Since Glee often touches on family issues, in fanfiction, Shelby and Puck might form a sort of surrogate family for each other. For example, Puck might find the motherly figure he lacked in Shelby, and Shelby might see Puck as a son - like figure she can nurture and help along the way.
Another theme is redemption. Shelby has made some mistakes in the show, and in fanfiction, she is often given the chance to redeem herself. This could be through her actions towards the glee club, or how she treats individual characters. It gives readers a sense of hope and growth.
There could be a fanfiction where Puck discovers Shelby's past and tries to help her overcome some old traumas. This would involve a lot of emotional conversations and character development for both of them.
One common theme is redemption. Puck especially has a bit of a rough past in the show, and fanfiction often explores his journey towards redemption, with Finn sometimes playing a role in that. Also, the theme of family comes up. Given their different family situations, fanfiction might look at how they support or envy each other's family situations. There's also the theme of loyalty, as they are part of the Glee club and have to be loyal to their friends there, which includes each other.
There are often themes related to growth and change. Puck has to grow up fast when he becomes a father to Beth. Fanfictions may depict how he matures over time. Also, the relationship between Puck and Beth's mother can be a theme. It might explore how they co - parent or if there are any romantic feelings still there. Sometimes, the theme of acceptance is present, like how the other Glee club members accept Puck's new role as a father.
A theme that often shows up is self - discovery. Mercedes and Puck are both complex characters. In fanfiction, they might go on individual journeys of self - discovery, and their relationship could play a part in that. For example, Puck might learn more about his sensitive side through his interactions with Mercedes, and Mercedes could gain more confidence in herself and her talent because of Puck's belief in her.
One common theme could be the exploration of unexpected parenthood. Since it's mpreg, it's a very different take on having a child. Another theme might be the relationship between Puck and Finn, how they deal with this new situation together or separately.
Another theme is redemption. Puck has had his share of missteps in the past, and in fanfiction, there's often a story of him redeeming himself in the eyes of Quinn and Beth. It's about him becoming a better person and father.
Another option is Tumblr. There are often posts about Glee fanfiction, and some users might recommend or even post their own Puck and Shelby fanfictions. You can follow relevant Glee tags or search specifically for what you want.
One great Glee Shelby and Puck fanfiction is 'Shelby's Influence on Puck'. It shows how Shelby's presence in Puck's life helps him grow as a person and as a singer. It has some really heartwarming scenes where they bond over their shared love for music.
Will Shelby could be a source of inspiration in Glee fanfiction. His passion for music and teaching can be a driving force for other characters to pursue their dreams.