Tudor Submariner Stiff Crown

[Andrew.I01]

Hi all,
I am new to this site and I am wondering if anyone is able to help me with this.
I have this Tudor Submariner Prince Oysterdate (7021) where the crown seems to be very stiff. The crown is stiff every time I try to set the time, especially when I screw down the crown. Granted this watch probably hasn't been clean for a while, but I was wondering whether or not this is normal? I have not opened the case back as I feel I do not know what I am doing, nor do I have the tools to do so.

Also does the 7021 movement have a quick date function, or do I have to continuously set the time to change the date?

Thank you for your help.