Test the waters before you do a full install, and mention how you value XP, if you want to keep it, do you have Recovery Media, a Backup Image, Do you have important files on there etc. Remember, you have Complete Access to your Windows Drive via. puppy...so be careful if you are exploring the file-system. The benefit is that we can save files to the windows folders if we like, or just save them back to the file system on USB. The Dell would be a good place to practice installs and just the basics etc. if you don't mind possibly messing up XP.
Not having internet will be very limiting if experimenting with puppy and installing any OS can be dangerous to the existing OS. Perhaps you should stick with a LiveUSB and boot from the Laptop, or Dell just to get an idea of what it will be like. Puppy will ask you if you want to save at the end of a session, this is for any software and settings that you have made during your use. You don't have to Save but If you choose to Save, Save back to the USB just to be safe. You can Save to any OS Folder on the drive/HDD, but that can be risky until more is learnt.
I'm not real familiar with puppy, nor a computer pro...just trying to get you started. There will be better help along soon.
Speccy Chart is always good to add to the start of a Thread, or at any time in a thread if desired. It can also be put into your Signature so that it is visible at all your posts.
With screenshots, basically all you need to do is Host them to a Hosting site like PhotoBucket, here is a tutorial.