How important is a server management?

I was wanted to know how important a server management is. Right now I can’t afford one. I need to know what they exactley do. Is it important to upgrade things? Is it easy to learn it myself? I currently don’t have lots of experiences with servers. I just have one for 3 months and haven’t got any problems yet. I’m have an offsite to if anything happens with my server I still can get the files back?