You can use :lopen to open window containing error/warning lines. After that, navigate to each of them.
The actual answer is that you can use :lnext to jump to the next error, or :lprev, or ]l and [l (those are lowercase Ls) if you have vim-unimpaired, which you do, because you shouldn’t use Vim without it.
This will not actually jump to the next red/error highlighted text group, but will jump to whatever your syntax plugin dictates is an error (and populates the location list). It is impossible in Vim to jump to a specific highlighting group, because no one has bothered to figure out how yet.
The plugin SRDispHiGrp comes close, but if you couldn’t tell from the name, is too convulted and confusing for human use.