9500 character post limit, you were lucky to get what you got.
Somehow I don't feel lucky. 8)
The 9500 character limit does not apply to attached code.
9500 characters is more than plenty to write a sketch that demonstrates that a relay can be toggled on and off every second.
9500 characters is more than enough to verify that the temperature sensor can be read and the value printed to the serial monitor.
9500 characters is more than enough to verify that you can write to the LCD.
Writing one huge program that does everything, and is full of delay()s, is not the way to approach programming.
Develop a series of little sketches that demonstrate that the individual pieces all work. When you know that that happens, start combining them, two at a time. If, or when, stuff doesn't work together, it is so much simpler to detect why.