Need model rocketry help/advice

Anyone here done some/lots of model rocketry before? Because I am reaching out to ask if it is possible to have 2 engines or 3 engines at the bottom of your rocket (this is due to engine power regulations in my country)

My this I mean that imagine you are looking down the body tube, there would be three engines all together in a triangular or two engines side by side structure.

If so, how would I ignite them all at once without one igniting before the other(s).

Thanks!