"You and I want mangoes."
Translation:तुझे और मुझे आम चाहिए।
I am using other learning tools. One says chaahiye is like saying "is important" or "is necessary" (you really need it) and the is is built into the word in a polite way -iye. Thats why you use mujhe. So its like saying: To me, ... is necessary or important. Hope this helps.
तुझे is a form of तू and is the least formal version. You should only use it for very close friends and family who are about the same age as yourself. तुम्हें is a form of तुम and can be used for everyone who is of age with you or younger and someone older than you when you want to convey intimacy. If you want to be even more formal than तुम्हे, you can use आपको which is a form of आप.
'Jha' is झ which is distinct from इ (i).
So, to get झे, you need to type झ and े. This is probably Shift+'O' and 'a' on your keyboard.
The ् key which you call the letter-joiner is not for consonant+vowel combinations. It is for consonant+consonant combinations. For example, to get म्ह (mha) in तुम्हें, you need to type म + ् + ह.