I personally learned to beat match using commercial Pop & Dance music, which is quite commonly 128 beats per minute (BPM). The beauty of 128BPM music specifically is that a new instrument or vocal is usually introduced into the song every 15-secs EXACTLY, meaning that you can often predict when the next part of a track is coming in just by looking at your time counter. In the same way, extended mixes will lose instruments and vocals towards the end of the track, which makes it a great way of mixing the start of one track into the next as instruments and sounds are removed and added to the songs respectively.
Look out for any popular tracks by Calvin Harris (‘Let’s Go’, ‘Feels So Close’, ‘C.U.B.A’ etc), Martin Garrix (‘Animals, ‘Wizard’) David Guetta (‘Bad’, ‘Without You’) or even the Black Eyed Peas (‘The Time’, ‘Don’t Stop the Party’) – all of these tracks are exactly 128BPM and will overlap seemlessly if cued at the correct point.
Also, when buying/downloading these kind of tracks, always try and find a Club Mix or Extended Mix if possible. This will usually have a good 45-60 secs of intro AND outro without lyrics which will be better to practice with than the standard (and shorter) Radio Edits. One great example is the Extended Mix of ‘We Found Love (Feat. Rihanna)’ which is still an inclusion in many of my club sets and is really easy to mix in and out :o)
As your confidence in mixing 128BPM grows, try mixing in 127BPM tracks (by adding 0.8 to the track’s tempo) or 129BPM (by slowing the track down by 0.8). It gets harder with slower tracks like 125BPM, where 2.4 tempo change is needed to keep beat-matched with 128. It’s all about practice. My only suggestion is, try not to mix anything that differs in tempo dramatically. From early experience, nobody wants to hear their favourite House track sung by Alvin and the Chipmunks on speed.
Enjoy buddy.