A couple of comments & suggestions.
Cannot convert... errors -
The array syntax can be confusing because once you define MyArray[n], then MyArray (without the brackets) is automatically defined as a pointer to the fist element of MyArray. If you use a single-subscript with a two-dimensional array, like MyArray[n], that becomes a pointer.
When you get a "Cannot convert..." error, it's often caused by trying to assign an element-value to the pointer:
MyArray = MyArray[3]; //wrong!
MyArray = X; //wrong! (Unless X is a pointer)
l-value errors -
l-value means left-value. Something is wrong with the "variable" on the left side of the equal-sign. The "unknown", belongs on the left.
X = 6; // l-value OK
6 = X; // l-value error
X = Y + 3; // l-value OK
Y + 3 = X; // l-value error
PROGRAM DEVELOPMENT & DEBUGGING - The real solution to your root-problem -
It is very difficult (and frustrating) to debug a program with many errors!
The error messages aren't always helpful. The compiler doesn't know what you're trying to do, and compilers are easily confused... You didn't want to "convert" anything, but the compiler "thought" that's what you were asking it to do. The first error message usually points to a line near the actual error. Linker-error messages don't reference line-numbers and they can be difficult to decipher.
So, do NOT write your whole program before you compile and test it. Experienced programmers write and test small sections of the program at a time.
Write one or two lines of code, and then test-compile and test-run your program. Debug as required. Add one or two more lines and test-compile, test-run, and debug again. As you gain experience and confidance you can write larger sections of code between test-compiles and test-runs.
Now, it takes a bit of practice to learn how to develop your code in this way. Of course, you can't write the code to call a function before the function definition exists, etc.
When you write a function, make an empty function first. If there is a return value, include a known "dummy" return value. Add a few lines of code at a time to the function body 'till it works completely.