How long does it take to make own blockchain?? and beginner is also easy to do it?
Of course not, you need to have atleast basic knowledge and info for creating such block chain, and planning is also important.
Like what type of Blockchain you want to implement?
You need people also to work under your block chain since you are merely needs to compete to other Blockchain server.
You need to market your block chain in order for it to expand to win over some perspective customers.
Don't take anything to be easy pal.