Can Serato DJ detect the BPM of my track?

The short answer is yes.

Serato DJ can detect the BPM of your tracks while it analyzes files. The "Set Auto BPM" option must be ticked before you start analyzing files, then if Serato DJ is confident the auto BPM estimate for a track is accurate it will be written to an ID3 tag in the file.

The auto BPM function will not be applied if the track already contains BPM information. If you know your files BPM will fall within a certain range, use the range drop down to avoid double or half value BPMs being calculated.