Leetcode is a great way to polish your skills. When I was your age, I read programming books and made projects I cared about, it’s turned out very well.
I’ve helped a few others learn programming, practice and working on any project at all always help more than anything.
Some of them perhaps, but the home is understated if anything, especially with interest rates in the 7% range. They’re also not accounting for taxes, utilities, repairs, and insurance