In British English we do have this distinction. Practice is the noun. Example : 'Practice makes perfect' OR 'The Doctor's Practice (The place where you go to meet/consult the doctor) Practise is the verb. Example : 'I am practising for my speech tomorrow' OR 'I practised many times before I finally knew how to do it.' Hope this helps! :)

American English doesn't usually make this distinction. Practice is used for both verb and noun. You are not wrong; you're just using a rule that hasn't been used in AmEnglish for a long time. I believe it is alive and well in BrEnglish.

Hmm that's interesting. I have been living in Britain for some time now and have done my schooling here but I don't think I have ever seen this rule being played out in British English either. But thankfully, I don't think the reader would be confused if you wrote "practice" or "practise". It's one of those things that no one really pays much attention to anymore so they have just become coalesced piece of grammar.