I have 2 distinct loops or sets of code
A block of code/function is one thing. A loop is something else, entirely. Which do you have?
Once it starts executing a loop it must never return. The 2 loops contain different data sets and multiple if statements, so using a main IF sensorvalue decision doent work.
Again, a terminology issue. If you want one thing to happen forever if on reset the sensor reports one thing, and something else to happen if the sensor reports something else, then simply don't read the sensor again.
i am thinking that a case statement is suited but I am confused by the need for a Break, as I dontbwant to break out of the loop once entered.
A switch statement is just a shorthand notation for a series of if/else if statements. If the it/else if construct won't work, then switch won't either.
Can I have multiple void loop(), and how would I enter each one?
No, but you can have multiple functions that never return that appear to accomplish the same thing.
But, really, why do you want to do something forever based on a condition at reset? If the condition changes, shouldn't the Arduino's actions?