What are the castles like in Scotland? are they livable? or all falling apart? Never been,,,just curious.?

There are a mix of both inhabited castles like Dunvegan Castle or Inveraray Castle and ruins like Urquhart Castle or Dunottar Castle. 

If you have never been to Scotland I highly recommend it. It has a raw majestic beauty.

Some are in good condition, some are not easy to find out online.

Here is the 18th Century Fort Cumbernauld, built in what is now the centre of Cumbernauld to defend against rebels in the Jacobite Wars:

As with castles in most parts of Europe, some are liveable, some are in ruins. Many are now "heritage" centres" of some sort or other, not lived in but open to the public either free or upon reasonable payment. Check the website of the Scottish Tourist Board for a few good ones to visit.

I assume that you are not enquiring with the notion of possibly purchasing a castle.

Some are habitable, some are ruins

Depends on the castle

many are ruins.

Well, some are livable and some are falling down, some are more livable than others depending on your idea of livable, and some may not be livable but aren't quite falling down. You ask as if they are all in the same condition. That's like asking if all 2010 Toyotas are in good shape.

Search engines are still useful and quicker

https://www.bing.com/search?q=scottish+castles&for...

Many of them are lived in. Try googling it and see for yourself.

Start with Balmoral.