I’m working on Saturday, off on Sunday and then on a course Monday to Wednesday. So on Thursday morning when I insert my card how would I record this also what about when you are on holiday?
You could record each day onto the card using the manual input facility - but that’s way too much faff (and far too likely to result in erroneous input(s) being recorded).
In order to remain totally within the letter of the Regs, you should make (written) manual entries for each day on a piece of printout paper (or on the back of a paper chart), keeping one copy of each with you for the next 28 days and handing another copy in to your employer (alternatively keep just the one copy with you and then hand that copy in after 28 days).
It depends. How are you on manual entries a digicard? If you can do that its easier to keep it all on there.
I’m back in tomorrow so I’ve got to add what I did after I finished on Tuesday (travel time) and a CPC course on Wednesday plus my rest Thursday and Friday. Personally I’d rather do that than have bits of paper (which I’m useless with)
Is the course part of your work 
If not then, as well as holidays, there is no need to record anything because all non recorded time is assumed to be rest by the authorities in the UK
Going abroad is different as a letter of attestation is needed for holidays