The series was filmed in Adelaide, South Australia including on location at Marryatville High School and Mercedes College.

She must navigate the social and personal issues of her early teenage years, while also dealing with the pressures of her gender identity, which is largely private at the beginning of the series.

Jan Stradling from the ABC and Bernadette O'Mahony from ACTF served as the executive producers of the series.

First Day and the associated short film have received a positive reception for its representation of diversity in transgender children.

However, she struggles with being bullied by Isabella, a classmate from her primary school, who threatens to reveal her secret, and taunts her with her previous name.

Hannah lives with her mother, Amanda; and her father, Steve, who try to protect her from the harm of external situations, which sometimes leads to disagreement and conflict.

Hannah starts to feel lost and ostracised from her friends and peers; in searching for a place to fit in and belong, she begins a social club for LGBTQIA+ students.

[7] Kalceff was motivated to increase visibility of the LGBTQIA+ community through telling a story about a transgender teenager, after being inspired by a family member who was transitioning.

[5] In June 2019, a miniseries based on the original short film was ordered by the Australian Broadcasting Corporation to air on ABC Me.

[6] Also titled First Day, Macdonald and the original creative team were named to return to the production, which would be told as a four-part series.

[13] Kalceff wanted to continue Hannah's story and show the character dealing with regular teenage issues, while also addressing microaggressions towards transgender identity.

[2] Reviewing the full series in 2020, David Knox of TV Tonight described it as "the most inclusive, most authentic kid's drama since Dance Academy".