Watch the letter order of the statement:
ΔABC ≅ ΔDEF
Where point:
A = D
B = E
C = F
Take any sides and use the corresponding labels correctly to make them congruent.
Let's say I take side AB.
ΔABC ≅ ΔDEF
Refer to the correspondence chart we did above ^^^. As you can see that AB is equal to DE. You can also see this by referring to the first two letters in the triangle statement.
One pair of congruent sides: AB ≅ DE
Now for the angles, it's basically the same concept.
I'll take angle ∠ABC or ∠B. (Note: Always refer to the middle letter when there is a three letter angle label like ∠ABC)
Refer to the chart and what do we see?
We see that:
∠ABC = ∠DEF
or
∠B = ∠E
One pair of congruent angles: ∠ABC ≅ ∠DEF or ∠B ≅ ∠E
Note: you can also do this with any letter combination, order, etc. ONLY IF you can correctly order their corresponding points.