While looking for some astronomy events to watch (without telescopes) in the future I found that on the 21st of August Saturn is in conjunction with Sun. Sorry for my lack of knowledge but what does this mean? And is it something that would be interesting to see?

In conjunction in astronomy means they appear in the same place in the skies. From google, the definition is:

"The inferior conjunction of an inferior planet is its position when in conjunction on the same side of the sun with the earth; the superior conjunction of a planet is its position when on the side of the sun most distant from the earth."

Hope that helps. It won't be much to look at because obviously you can't look near the sun anyway, unless you have a telescope with a solar filter.

Sorry for my ignorance, but does a solar filter have to be fitted on a telescope or can you buy them to look directly at the sun with the naked eye?