Hi Logic Guy,
In the Logic 101 course you'll find info on raising the I/O Buffer Size in Preferences > Audio... which will increase latency but be kinder on your CPU.
Other advice is to make sure you're not using more plug-ins than you need. e.g. run one instance of a multi Omnisphere... and not 8 instances... or if you're applying the same reverb to multiple tracks, place one of these on an Aux and send to this Aux from all tracks.
Hope this helps,