Does 沙 mean sand? Thank you very much.

Yes, but it is also used for transcribing foreign names into Chinese.

I would like to thank you for your help. Greetings.

Mind that often the two-syllable form, 沙子, is used.

Often best to learn words, as characters are not usually one-to-one translations e.g. dou4sha1bao1 豆沙包 is rather tasty but doesn't contain sand (here 沙 means granulated I suppose), and most common use of this character is probably in the word for sofa or salad or something like that (as xiaokaka says)