HOW TO GET TO SOFIA EASILY?

The cheapest and most affordable airlines are: EasyJet, WizzAir, RyanAir, which offer daily flights to Sofia Airport, Terminal 1, Terminal 2.

THE OFFICIAL SITES OF THE AIRLINES ARE:

https://www.easyjet.com/en
https://wizzair.com/bg
https://www.ryanair.com/gb/en/
HOW TO GET TO SUNNY BEACH EASILY?

You can take a flight to Burgas, Varna or Sofia.  From those cities there are many busses to Sunny Beach, but you have to reserve your ticket in advance. The closest airport is Burgas.