Temp gauge could be something as simple as the sender's connector has popped of the sender. 5 second job once you've found it

If it's creaking when you brake, and when you lean on it, you might just have a slightly binding caliper or drum that needs seeing to. By the sounds of it, it's the drivers side front caliper. For a quick check, jack it up on each side and spin the wheels by hand - they should both spin quite freely.