Installing ponds require planning, time and depending on your design a lot of hard work. Just remember Rome was not built in a day!
I suggest that you read every section possible on this page before you decide to start building your pond. You need to plan everything from where the pond will be in your garden to what equipment you need.
Are you able to dig and move barrows of dirt or will you need to hire a mini digger?
Are you planning on having a waterfall or stream?
There are loads of questions you could ask, and I could go on all day, so I will just crack on.