Welcome to the forum! Hate to say it, but a reticulated python would be an awful first snake. Intelligent (for snakes), incredibly powerful, highly instinctive and they can grow to twenty feet. And if even a half grown reticulated python got angry or mistook you for food, it wouldn't matter how sorry it was afterward...
Yes, they could live in a very well heated room with high humidity, (think jungle) but you wouldn't be able to live in the same room. For safety reasons.
A very strong cage, (8 feet or longer) would be far preferable.
And speaking of cages, do you mean that your pets are all in a shoebox together under your bed??? That's not good for them. At all.
Get your little crabs out from under your bed, into a nice terrarium where you can see, watch, and enjoy them. And get your turtle some UV light to bask under to keep him healthy and fix up a large terrarium with a natural type habitat to run around in! Or swim, depending on the species.
Make sure your current pets are very well set up before getting new ones.
A smaller snake like a corn snake, garter snake, king snake or ball python would make a much better first pet snake. They'll need a secure cage with a safe heating element, water dish, places to hide and so on, but they'd be easier, calmer and safer than a reticulated python.
And good luck.
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0.2 chickens (Falcon & Condor)
0.2 dog mutts (half ownership, only mine when they misbehave, Lucy & Amy)
0.1 Halflinger horse (Crissy)
0.0 Arizona Mountain Kingsnake (coming soon)
1.1 parents
Still searching for 1.0 WC human