Briefing
grep <pattern> <file> prints only the lines that match. The log is hundreds of lines of noise, but the flag starts with TERMUX{. Search for that.
Objective Search access.log for the flag.
Stuck?
Take it one step at a time. Ask for a hint here, or type help in the terminal to
see the commands this challenge is about. Typing hint works there too.
That is every hint. If you are still stuck, run help in the terminal.