Best long-term planning on a tight budget [v3]

Spent the last few weekends digging into this and the deeper I go the more questions I have. Posting this here because the relevant subreddit has gotten too noisy lately. Not sure if this is the right place to ask, mods please remove if it is not.

There is a lot of conflicting advice online and most of it is from 2019. Quick context: I am relatively new to this and trying to find my footing. The trade-offs here are not obvious to me and I keep flip-flopping.