I am having issues with calculating DV,
Most of the replies I will get are going to say: Get KER.
I installed KER but I have no idea how to use it, it's too complicated.
Thanks.
One of the hardest things to do in KSP is to rendezvous and dock with a ship in orbit, you can watch scott manly's tutorial, and if you find it too hard then there is a tutorial in the tutorials section of the main menu.
Good luck!