Flame graphs look intimidating. Three facts make them readable.
Width is time
The wider a box, the more samples landed in that function or the functions it called. Look for the widest boxes first.
Height is the call stack
Each box sits on top of the function that called it. The top edge is where the work actually happens.
Colour usually means nothing
In most tools the colours are random, chosen so neighbouring boxes look different. Do not read meaning into them.
What to do next
Find a wide plateau near the top. That is code spending a lot of time doing one thing. Start there, change one thing, and profile again.