Monitoring active query step using only pure sql

I would like to monitor actively running query on Oracle. What I mean is to gather info about:

1. Actually running step. (What is currently db engine doing in this query)
2. Actual query plan used in execution.

I know that there is a lot of useful tools to perform such a checks, but in my configuration I can use only plain sql queries to database.
Any ideas where I can find some resources how to perform such checks? Most of tutorials are oriented on using specialized tools for db query monitoring.