and I was wondering if there was a way to store all the integers into an array or vector so that I can transfer the values into a 2-dimensional array that would represent a sudoku board. Any help would be appreciated. Thank you!
You can use .lines() to get iterator of lines.
And for each lines, you can use .split_ascii_whitespace() to get columns delimited by ASCII whitespaces.
Then you can .collect() them and create Vec<Vec<i32>> (or whatever you want).
BTW, you won't be able to do much in Rust without crates. It's normal to use plenty of crates even for most basic stuff. While some languages prefer to have everything built-in and not use dependencies, Rust is the opposite: it intentionally has a small standard library, and made it easy to rely on crates for everything.