is this correct: Prince Charles is King of England the exact second that the queen dies ?

Charles will be king but it will not be until the coronation that he will be the"true" king and be wearing the crown. Carmella will not be Queen. She will be the Queen Consort at most and may never be given that title.

He will be King of the United kingdom and several other counties.

Yes he is it is the order of succession

No, Charles will become King of the United Kingdom of Great Britain and Northern Ireland, along with 15 other Commonwealth Realms the moment his mother dies. England stopped being a separate kingdom in 1707. Anne Stuart was the last English monarch. The Acts of Union of 1707 ended the separate kingdoms of England, Scotland, and Wales to form one united realm. It isn't pedantry to give correct, full information about the proper titles as some rabble-rousers like to say, rabble-rousers who are all for being ignorant of full facts. England is only part of the realm, and to mention only England is to forget Scotland and Wales.

Camilla, as the wife of the king, automatically becomes Queen CONSORT, the non-reigning spouse. Spouses don't have hereditary powers to reign and are there to support the monarch.

The Coronation is a solemn blessing service of the monarch that takes place about a year after the death of the late monarch. The service brings the kingdom together for prayers, not just for the new monarch and spouse, but for the realms. It's more than a mere formality but a symbol for unity, connection.

no, in this time of diversity, queen meghan will be installed

Almost. Provided he survives her, of course, he will become King of the United Kingdom (which includes England) the moment the current Queen dies; and his wife will become queen. That has always been the rule. Coronations take a long time to organise, sometimes a year or more, and you can't simply not have a head of state for that long.

Technically, accession of the new monarch occurs at the moment of the death of the previous one, legally this is affirmed by the accession council.

A Queen Consort automatically acquires that title the moment her husband becomes the monarch, or in the case that a king ascends the throne as a bachelor, the moment the priest declares the couple married at his wedding ceremony

Yes he will become King, the moment the Queen dies and the coronation is always held later after the previous monarch has been buried.

The Duchess of Cornwall like any woman married to a British King, is Queen Consort, when he becomes King.

The Queen's mother who married King George VI had the same title although she was usually just referred to as the Queen.

Yes, that is all correct. Pedants will quibble about the England/United Kingdom thing but they need to get a life.

He will not be king of england, he will be king of the united kingdom and all his overseas dominions,camilla will be his queen consort and the coronation usually takes place a year after he becomes king, it is a lot to arrange and the court is in mourning for a year after the monarch dies.When his mother became queen, although her father died in feb 1952 the coronation was not held until june 1953, a part of that was because it was thought that the weather would be ok, in fact it rained for most of the day!