How do you know how many lines/words there are in the file?

> char todos_fich[i][2];
Aside from the fact that i is zero at this point, this doesn't create an array you can just extend at will.

> for(j=0;j=1;j++)
Refer to your book for proper syntax. Say

> fclose(elementos.txt);
This takes the file handle, Elementos as the parameter.

Passing Elementos as a parameter does no good. You'll get the same effect by making it a local variable.