Gold plated jewellery is commonly available and even popular with many people. Mostly the best one can say about gold plated jewellery is that it is cheap.
It is not as good as solid gold, even the 10 karat gold jewellery as. To start with it is usually a base metal, such as nickel or steel, and the gold plating, regardless of the thickness, will eventually wear away.
Gold plating can be thick or thin, usually thin and it is never 22 or 24 karat but usually 10 ot 14 karat gold. This is actually better as is a bit harder and longer lasting. 10 or 14 karat gold has been mixed with other alloys such as silver, nickel and zinc for example and so is more durable than pure gold which is quite soft and malleable.
But the amount of gold in gold plated jewellery is going to be extremely small and certainly not worth the price one pays for it. It also has virtually no resale value regardless of how much the value of gold increases.
If, for any reason, you find it necessary to buy gold plated jewellery make sure that the gold is an appreciable thickness. It is no good if it becomes worn off after a week or so with use. Also you need at least 14 karat gold and not less otherwise it will hardly even look like gold.
18 and 22 karat gold is ok but it is very unlikely you will ever find that degree of gold in a gold plated jewellery article.
The care and maintenance would be the same as for any gold piece. Wash in warm soapy water and rinse well ensuring that all the soap is fully removed. Then dry fully so no water remains to rust the metal alloys.
However, gold plated jewellery has it's place and can be quite useful, perhaps to replace a more valuable piece for example, so is not entirely bad and it does enable those who are not fortunate enough to be able to own pure gold a substitute.