The thing I wish more people said plainly: your first month is mostly calibration, not “building an audience.” You are learning which topics you can repeat without hating them, how long it takes you to make something, and what people actually respond to versus what you hoped they would respond to.
I would start with a small rule set instead of a big content plan. Something like: post 3x/week for 4 weeks, use 2 repeatable formats, write down why you think each post might work before publishing, then review the results once a week without changing everything daily.
The mistake I would skip is over-polishing before there is any signal. Make it clear and useful, publish it, then let the pattern of replies/saves/questions tell you what deserves more effort.