If you come to Bulgaria and are in Sunny Beach, and you need to purchase a mobile phone or a card from a mobile operator, then this is not difficult.
In the very center of Sunny Beach you can buy phones and SIM cards from different operators.
This can be done in one place - in the "Condor" store.
Find it is not difficult.
The store can be reached by public transport - stop "Center".
From the stop you need to walk 100 meters on the same side.
Near the store you will see mail. You can also use her services.
In the "Condor" store, you can purchase SIM cards from various Bulgarian mobile operators. Among them are "Telenor", "Vivacom", "A1" and "Mtel".
Near the store there is a paid parking, there are always places. Here you can park and go for a walk towards the sea.