I would not say that Oracle is easy to learn. I've been involved with Oracle for about 10 years now and I'm constantly learning new things, every day. The basics of Oracle are pretty easy. And the Oracle documentation and the many Oracle books on the market make it easier. The more advanced concepts can take a while to master.
I would never compare MS Access to Oracle either. Oracle is a full-fledged relational database management system (RDBMS). While Access is a relational database, it lacks criteria to make it a RDBMS. For one thing, there is no transaction control in Access. MS Access was designed as a single-user database. I cannot begin to count the number of times I've had to tell someone to restore their MS Access database from a backup because they let two users simultaneously update data and it corrupted the .mdb file. If you want multiple users to access your data, then stay away from MS Access.
Oracle does have a GUI tool, if you are so inclined. It is called SQL Developer and it is available for free from Technet.
This was first published in April 2006