Is もし a conjugation in this sentence? and can anyone explain on the ければ at the end?
Here is a link that may help with your questions. http://www.guidetojapanese.org/learn/grammar/conditionals
If it is clear from the conversation before the sentence "If you want." that the person who wants is "you", then you could get rid of あなたが. Also, since もし is only there to stress the "if" meaning that is included in ければ, you could get rid of もし. The result would be 「ほしければ。」「ほしいなら。」「ほしかったら。」
Example1: 「そのガム、おいしそうですね。」「ほしければ、どうぞ。」「いいの？ありがとう。」 Example2: 「お金がほしいなら、働きなさい。」
Could someone explain the ければ form? I've never seen it before.