Questions & Answers about Kao početnica još radim puno pogrešaka.
Početnica is the feminine form of početnik (beginner).
- A woman would say: Kao početnica još radim puno pogrešaka.
- A man would say: Kao početnik još radim puno pogrešaka.
So the noun agrees with the speaker’s gender. Croatian regularly has masculine/feminine pairs like:
- učenik / učenica (pupil)
- student / studentica (student)
Kao means as / like and is followed by the nominative here: kao početnica = as a beginner.
With kao, Croatian usually uses the nominative for a real role or identity:
- Radim kao učiteljica. – I work as a teacher (female).
- On govori kao stručnjak. – He speaks as an expert.
You might also hear instrumental in some expressions (kao početnicom etc.), but in your sentence the natural choice is nominative: kao početnica.