You will no doubt need something to get through your training but don't expect it to be of any use afterwards. I have an original E6-B which I've never used since I got my first PPL. For years it sat in my flight bag, and every now and then I'd get it out to remind myself I still knew how to use it. Finally I faced the reality and it sits in my much larger bag of things I've bought for flying that I never use.
Especially flying a helicopter for recreational VFR, looking out of the window will get you everywhere (literally). You need to understand the effect of wind generally, but you don't need a computer to tell you that if your machine does 90 knots and there's a 20 knot headwind, you'd better allow a bit longer and make sure you have a bit more fuel.
It's only in the written - especially as I understand it the UK written - that you have to calculate wind-corrected heading to the nearest degree, or flight time to the nearest minute.