I notice you say you "bought this console", but Recalbox is a free to download OS / piece of software, so it sounds as if you have paid for pre built system, which isnt liked by the Admin on here (as they do all their work for free in their own time), plus, the microSD is external ???
You say you went into debt to buy it, but a Pi3B or Pi4 is under £40, a good case £8, and even a 128Gb microSD card is on Amazon for under £12, so I have no idea just how much you have paid.....
However, I will try and help.
You say you are a novice, but, if you dont learn a wee bit and get your hands dirty so to speak, you unfortunately wont get very far.
I have various setups of Recalbox 6.
One on a 128gb microSD card, and the other is a 16gb microSD card effectively just to boot up Recalbox, with my games on a tiny Samsung 128gb USB stick.
I recently bought another 16Gb Kingston microSD card from Amazon for under £4, installed Recalbox 7.01 on it, plugged my USB stick in, setup my controller, pressed Start, selected System Settings, and then Storage Device, changing it from internal to any external (or the name of the device attached if you prefer).
Once it rebooted, I shut it back down, and copied over all the bios files and overlay files into the relevant folders on the usb stick, plugged it back into my Pi3B, powered it up, and it found my games, and the systems Ive loaded so far, the scraped data has been fine, ie screenshots, game descriptions, into videos etc.
Ive also just tried a 2Tb Western Digital portable device, and it too is fine, although I had to use my official Pie power supply due to the power drain from it.
Now, MY setup worked, but thats because I had scraped all my own stuff before, and if I go into the files, there are no "absolute" path names, so it will work.
As your device is pre built, it all depends on how they have scraped their data, and if absolute path names have been used (ie they specifically refer to a specific named folder or sub folder that clearly wont exist on a usb stick), I doubt it will work.
Simplest way is to do the above, and try just one system.
You obviously need the bios files for any systems. Those are all pretty much still copyrighted, although a google or youtube (seriously) search for Recalbox 7 bios files" will probably turn up something - I will leave your conscience to decide!
Or, you could copy them off your microSD card (you will need to learn quickly how to use the software WinSCP if you do) and copy over the files to the usb stick in Recalbox/bios, making sure not to overwrite any ones already there with your older ones.
Ditto with the overlay folders and their contents if your system has overlays / bezels.