How to combine strings and text together?
I wouldn't use the String class, but instead use the C functions to concatenate strings (like strcat, strncat).

You can use the itoa function to convert an integer to a string, see:


  https://stackoverflow.com/questions/9655202/how-to-convert-integer-to-string-in-c


Or use the sprintf function.

These are all standard C functions which gives you complete control of the buffer sizes to use. Handy because the Arduino Uno has just 2 KB.