All this means that, if you already spent some time to read first paragraph, you could have read few lines more and check FAQ document too.
Don't worry, 4 GB user data / 1 processor / 1 GB RAM will be enough for a good start. Develop the application and upgrade (i.e. buy the full version of Oracle database) when necessary.
I guess you will not even notice those limitations during education / development process.
However, if you are worried about it, full Oracle version can be downloaded here. It is free to use until you start to make money with it - then you'll have to pay for it. (Note that Oracle XE, on the other hand, is FREE to develop, deploy and distribute).