The next step after basic introductions is basic sentence structure. We need to know how to say what something is. This is a pretty simple sentence.
これはりんごです。This is an apple.
それはりんごです。That is an apple.
あれはりんごです。That over there is an apple.
これ means 'this.' You use これ if the item you are referring to is near you.
それ means 'that.' You use it when the item is near the person you are speaking to.
あれ also means 'that.' But more specifically, 'that over there.' It is used when the item is a distance from you and the person you are speaking to.
は is the topic particle, again.
りんご means 'apple.'
で す makes the sentence polite (to be.)
____ ___ ___
This apple is.
Now, you can say what things are in Japanese.
これはほんです。This is a book.
それはかさです。That is an umbrella.
あれはぎんこうです。That (over there) is a bank.