How to change/edit/add your on live server

I have got live server running. How to modify/change/edit - how to work with your code that is on liver server?

I have tried to research, but i ran into a wall.

Common answer -GitHub/hook/ssh/

Well i cant use ssh to connect to my server and i failed to make hook work.

Any guide/tutorial will help help. I just want to upload code, have it localy and work on it.