What is the difference between tithe and first fruit?
There were two laws to the Jews about firstfruits. One of them (Deuteronomy 26:1-11) applied specifically to the first harvest after the Israelites conquered Canaan under Joshua. It was to be a thank offering for Godís bringing them into the Promised Land.
The other firstfruits offering was an annual offering (Leviticus 23). All that the Law specified was that the first of the harvest was to be brought. It did not specify how much. (And, of course, the first offspring of each animal was to be offered or redeemed.)
The tithe literally means one tenth. Every three years the Jews in the Holy Land were to give one tenth of all their produce to the Levites living among them, because that was the only support the priests and Levites received. Basically it was a 10% tax for the support of those who worked in the Temple.
Both the tithe and the firstfruit offerings ended effectively with the destruction of the Temple in 70 AD. There are some who would say that these only applied to those living in the Holy Land, and not to Jews living scattered among the nations. Also, of course, these laws never applied to non-Jews wherever they lived.