I respectfully disagree with one part of what Cleared4Approach said.
You have 6 months to learn
everything there is to learn.
Treat it like your life depends on it, because it does.
How many threads do we have here asking about 121 failed rides? Do you want to be average? Do you want to start class not knowing nothing about nothing or do you want to walk into class knowing pretty much everything about that airplane and you can regurgitate verbatim?
Throw a couple of hooks out and see if you can snag the actual manuals too.
Be humble and never stop learning.
121 world and flying a jet is a different parallel universe from what you’ve been doing.
Only the basic aerodynamic principles carry over, everything else is different.
The knowledge is out there.
Best of luck to you.