Hello @Jessie_Uddin and welcome back 
If you use the Search function (the magnifying glass icon at the top right of the main webpage) to look for “business card”, there are various topics that mostly deal with subjects such as layout and positioning of the content.
Here is one:
Krita 5.0 - how to perfectly center a shape or image on your canvas + a bonus tip 😮
The end result will be an image and the requirements for its size, file format, colour profile, etc, should be explained by whoever will be printing the business cards for you.
Depending on the printing service, there may be limitations in colour reproduction which should also be explained somewhere.
Do you have a printing service in mind and do they have a website that explains all that?
One thing I do know, for printing, is that there needs to be a ‘bleed’ area around the artwork to take account of the variation/tolerances when cutting the card and that’s about all I know.
Somebody with more knowledge in this area might come along with detailed advice.