hi There,
we didnīt start running our dog next to the bike until she was at least 1....but when we did, we first trained her with us riding a kids bike
Not a tiny bike but small and low, and we could easily stop ( or fall off) and be able to control her on the lead tight in by the side. When we moved up to a big bike it went really good, though only one time she got hit by the bike. The other problem we had was she would stop very suddenly for a poo mid ride. I had to watch her warning signs and be prepared to drop the leash or brake suddenly! After a year of really slow controled lead running( allways slow) now we can without a leash have her in the heel position while we cycle everywhere...she loves it
good luck, but wait a bit till your dog is older.
Annie