Count files and folders that are not hidden:
ls | wc -l
Count all files and all folders, including . and ..
ls -a | wc -l
Same, without . and ..
ls -A | wc -l
Same, but now we only count honest to god files, not directories or pipes or anything else.
find . -maxdepth 1 -type f | wc -l
See man wc, man ls, and man find for more info.