Have you tried writing flash fiction or a drabble (100 word story) to practice in first person without it feeling overwhelming?
Some things to remember while writing in first:
- the main character isn’t going to know everything that everyone else knows
- keep your writing active! Don’t get bogged down in the “I see this” type sentences
- first person can feel very intimate, so use that closeness to your character to your advantage
- since it’ll be an established first person narrative, there’s no need for “they thought” tags, but definitely utilize stream of consciousness thoughts from your character