I will have my PPL by then but think I'd like to have someone with me so I could enjoy an hour or two of looking at Orlando from the air.
As you are from the UK I assume you're training for an EASA or UK National PPL. That will not do you any good in the US. In order to fly an N-reg in the US, you need a US-issued (FAA) PPL. So it's not a matter of "I'd like to have someone with me" but rather "I am legally required to have someone with me".
The easiest way to make that happen is indeed to simply book a lesson with an instructor. If it's just one "trial" lesson, then you don't need to bring any paperwork, and no TSA or visa is required.
If you don't want the company and experience of a licensed instructor on board, you have two options:
You can get an FAA PPL that's "based on" your EASA or UK National PPL relatively easily, but it's still a fair amount of paperwork to go through, for just an hour or two experience flight. Search "piggyback PPL" or "FAR 61.75" for more information.
https://www.faa.gov/licenses_certifi..._verification/
Or you can go the whole way and obtain a standalone FAA PPL. This will require some lessons as there are bits in the FAA PPL syllabus that were not covered in the EASA/UK PPL syllabus. Plus a written exam (only one) plus a flight test. You will also need TSA clearance and possibly a visa.