I bought a 2000 tt quattro

You connect a Fuel Rail Pressure Tester and compare against the spec.

Articles and Videos on testing. It also has a pressure regulator.

https://www.google.com/search?q=2001+Audi+TT+Quattro+fuel+pressure+test

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a broken wire

Could well be the sensor/sending unit at fault as Dan states.
Could also be the oil has lost some of its viscosity, become thin and not enough pressure for the sensor to work with.
Had a similar problem with a Citroen some years back was advised to drain the oil, flush the engine out with flushing oil (please read the manufacturers instructions closely) fit a new filter and refill. This worked well for me, also cured a smoking problem from the exhaust.

The first one is either a low brake fluid or low brake pad warning light. The second look like a low washer fluid light

sounds like the fuel pump relay

if vechicle getting spark and fuel.timing could be off due to a worn timing belt.i would do a compression test see what condition the engine is in.

you have a abs sensor going bad have it scaned to findout which one needs to be replaced

The yellow light oil sensor on Audi TT Quattro is the warning message for the minimum oil level has been reached !!!
Check engine oil level by dipstick & fill up oil inside engine !!!

Most likely it's your low brake pads indicator that is making the noise and they need to be replaced soon before rotor damage happens.
Thank you for using fixya and be safe.

On a 2001 Audi TT Quattro the fuel filter is located forward of the fuel tank, in the right rear wheel well area. The fuel line clamps are a bit tricky. The change will improve performance. The owners manual does not even list changing the filter. But do it! use a Fram, and it fit perfectly. Good luck.