Sorry to be late joining this thread. For a beginner, I would not recommend a dial test indicator but one like this…

I have several DTIs, the best being a secondhand Baty and a new Mercer, but the device that gets used 95% of the time is this Starrett no.564 indicator. Mounted at centre height in a quick change toolholder on the arms supplied with the indicator, I can quickly manoeuvre it into pretty well any position. The pointer reads positive for movement of the stylus in either direction and the stylus head can be rotated through 360 degrees. It's discontinued now but I got one for £7 on eBay that was new but not working. I took a gamble that I could fix it and it turned into one of my best buys on eBay. There was a tiny amount of corrosion inside which was stopping it from working. It came in this rather nice wooden box…

It replaced a similar Verdict indicator I'd used for 30 years that didn't have the advantage of the rotating head. Of course, it's a comparator and no use for absolute measurement but in practice I rarely find the need to do the latter. I'd be interested to hear the views of others.
Andrew M