Upgradation of SAP

I am using SAP Business One 8.82 PL:10 . I want to upgrade to latest version of SAP. What is the latest version of SAP ? I want to upgrade in such a way that it should adjust with GST which will be launched in few months ?

We have about 10 licenses for 20 users. These users are using several add-ons. What is the costing impact of up gradation ?

There are some problems in database. For this I want to upload the database to SAP before upgrading. For is the url for uploading the database ? How much time is required for this process ?