there is + [one thing or uncountable noun]
there are + [plural noun]
Is there … ? / Are there … ?
Use there is for one thing or for something you can't count. Use there are for more than one. The place often comes after.
In speech and messages, there is is usually there's. There are has no short written form.
Use there isn't a for one thing, and there isn't any or there aren't any for things you can't count and for plurals. There's no and there are no mean the same.
Put is or are before there. Short answers repeat it.
There is tells the listener that something exists. After that, use it or they to say more about it.
In speech you'll sometimes hear there's before a plural (there's two buses), but in writing use there are.