once the tax setting is done for the respective countries. And if I have ticked automatically charge taxes. Where does this reflect? Is it added to the selling price I have manually corrected on the product page? How will I know what is the basic price charged and how much is the tax charged? what does the compare price mean?
Compare price is for offers, like if something is half price you can price it at £5 but show a compare price of £10 and people will see it's on offer.
In tax settings, make sure 'tax is included in product price' is unticked (else you are paying it out of your pocket rather than the customer having it added on).
People buying from countries where you have added a tax % will then have that much added on to their item cost, or overall cost if you tick 'add taxes to shipping rates'. They will see this at checkout and their confirmation, and you will see it on their orders.
I advise placing fake orders yourself with your own paypal so you can see how it works