Hi Yasin,
When I had a similar issue with my central locking I had an auto electrician have a look and diagnosed the fault to the drivers door locking mechanism. It cost me £120 to fix.
Obviously if it's not this then it could be the central locking module which will be a lot more to replace. In which case it might be worth you getting a diagnostic check carried out to see if any fault codes flag up.
With regard to your second issue, what kind of noise is it? If it's a whine then it could be the powers steering pulley or pump. But in my opinion the first thing to check is the power steering fluid. If it's low then there could be a leak in the system.
Cheers
Steve