Mistakes are a part of knitting. Often times we don't notice our mistakes until we have worked a few (or maybe many) more rows/rounds of knitting. Of course, if you choose to fix your errors, you can rip out your stitches back to the mistake and re-knit everything.
However, there are times when it's easier and quicker to ladder down a column, or a few columns. It can be intimidating at first, but with practice and patience, it's a helpful skill to have in your toolkit.
There's more to explore in the Learning Library!