"This place is really beautiful!"

Translation: 这个地方真漂亮啊！

[KevinAbel13]

My answer is in green but it says "you missed a space" what does that mean?

[PeaceJoyPancakes]

It's just human error in entering the accepted answers. Almost all of the hundreds of answers on the list have been entered with an incorrect space after "地方", so the program is just telling you what it sees.

[Shibboleth]

Agree. Very weird.....

[VWieVendetta]

What's the 啊？

[NasuSamaruk0]

啊 - the character that is used to express interjection i.e. enthusiasm, excitement

[KX3.]

It is not necessary here but conveys the aforementioned feeling.