Working as a “chain boy” is the usual way I guess.
I’m not sure there are any “courses” any more on this sort of thing but if you studied construction, there would be surveying elements within that.
I work as a freelance surveyor / engineer after jacking in my corporate nonsense job a few years ago but started as a Land Surveyor in the 1990’s on proper instruments, way before GPS. I worked as a chain boy for a year or so after doing an HND in Civil Engineering etc.
I am finding that there are surveyors and there are CAD technicians, not many surveyors seem to be capable of both. Im my opinion, it is essential as you survey with the end drawing in mind regarding string lines etc. As you already use CAD, you will have a good grounding for becoming a surveyor because you know what it takes to make a drawing, how to generate coordinates from it for setting out etc.
Get in touch, I might be able to give you a days experience if there;s a job I’m on near to you.