Every individual has a slightly different level of sensitivity and response to THC and the other cannabinoids. I usually recommend that new cannabis users who want to avoid mental disruption start with a 1:1 THC to CBD ratio.
The closer the CBD concentration is to THC the less likely you will experience the psychoactive effects. Once you have a sense of how the balanced products affect you, then you can venture up or down the ratio scale to manage symptoms and avoid psychoactive disruption.
If you fine that 1:1 is still to stimulating, you may want to try 2:1 or 4:1 CBD to THC.