Generally, there are no signs of your timing belt wearing or breaking prior to it happening, it is immediate and sudden with no warning whatsoever. So keep track of your milage and have it changed when the service limit as been reached. If you don't know when the last time your belt was changed, either contact the previous owned or be safe and get it replaced.

As far as the weird sound, your going to have to get us more info in order for us to find a resolution.