When an expression has multiple operators, Java follows operator precedence rules to decide which operation runs first. This is the same idea as "multiplication before addition" from math class.
Here is the order from highest to lowest precedence for the operators you've seen so far:
!, ++, -- (unary operators)
*, /, % (multiplicative)
+, - (additive)
<, >, <=, >= (relational)
==, != (equality)
&& (logical AND)
|| (logical OR)
So in 3 + 4 * 2, the multiplication happens first, giving 11. In a > 5 && b < 10, the comparisons happen before the &&.