The first thing to do is to draw a plan / layout of what you want to do. Like a map of where everything should be. If you can do it to scale it is even better as it will help you work out measurements of everything you need - but you may get away with just a rough outline.

Ring around / drop into a few landscape places and explain you plan and ask them whether they do deliveries (most places will for a cost). They will literally just dump the dirt or whatever in a pile and it is up to you to move it where you want / need it - so you will require a wheel borrow and other equipment. Otherwise you will probably need to hire a trailer or ute to transport the stuff.

In my experience - DIY is MUCH cheaper then hiring someone, especially if it is simple work. However, landscaping is VERY labour intensive and it will likely take you much longer to do things then a professional.

You will also need to work out if you need to hire any extra equipment (ie, like a dingo to flatten / dig out / move dirt around the existing landscape). These things can be easy to use, but very daunting if you have never used one before. And if you haven't used one before, you can definitely expect it to take you much longer then someone who has experience.

We landscapes our investment property ourselves, very very basic design - it cost us about $2500 in materials and equipment hire (wheelbarrow and trailer we already had) and almost a week in labour (with two strong very handy men and myself doing it). The cheapest quote we got for the same thing was $6000. The professionals would have got it done in a weekend easily.

You need to weigh up the pro's and con's and decide for yourself which makes more sense.