Enhance My Python Telegram Bot

My Telegram bot, scripted with python-telegram-bot library, needs to be thoroughly checked for proper functionality and enhanced with some new features.

Key Tasks:
- Implement data logging to keep track of user activity and system errors.
- Add a set of custom commands focused on information retrieval.
- Conduct a comprehensive review of the bot to ensure its operating as intended.

Ideal Skills:
- Proficient in Python and the python-telegram-bot library
- Experience with bot development
- Familiarity with data logging and command creation
- Ability to debug and troubleshoot system errors
- Capable of implementing user activity tracking