Most of the work we did was plotting Foul water and Surface water drains onto developer drawings, so this involved chamber inspections (really not as bad as it sounds, the smell isn't that bad!) taking depths, photos of the conditions, positions relative to buildings, height of the manhole above sea level. so fairly basic things like levelling and measuring. This has become much easier with the use of laser equipment, where depths can be taken without needing a measure tape, levelling done without the inaccuracy of the person trying to read off the mast for height etc. I was still trained how to use the normal levelling tools.
After collecting the data I had to work out the gradients of the pipes based on the height above sea level to the manhole, the depth, and the length of pipes used in relation to other buildings.
The work I did was quite basic compared to what I've heard other surveyors do, but there are many areas within the building trade where surveyors are needed. Might be worth trying a few job agencies to see if they have companies offering training and see how it goes from there. As a summer job I quite enjoyed it.