There is one major problem with DotA: Being dependent on other people.
There is a huge difference between a match of people with low skill, and high skill. There are many things in DotA which you can take advantage of, some of which you never knew until you saw it the first time. Like for example pulling.
Anyway I won't tire you with that, since your problem already starts with controls.
Just keep trying and eventually you'll figure it out.
For camera movement you just move to a side of the screen, like with any RTS game.
You can also click on the minimap to see a place of the map.
There are many guides on this website and on other websites, you'll easily get drowned by them.
Here is a guide about basics:
And well, controls... Really just getting used to, try stuff against bots. Play at least 10 games against bots with one hero. If you want to try a different hero, again play several games against bots.