You asked
Canon eos 7d mark ii vs canon eos 750d?
The 7D Mark II and the 750D share a lot: both are Canon EF-mount APS-C DSLRs with a 1.6x crop and no in-body stabilisation, so you'll want stabilised lenses for slow shutters either way. The 7D Mark II is the one I'd pick for fast action. Its page calls it a tough, fast body long popular for wildlife and sport. The 750D is newer (2015 against 2014) and gives you more resolution, at 24.2 against 20.2 megapixels.
Both bodies take the same lens range, so choose by subject. For everyday use, try the Canon EF-S 18-135mm f/3.5-5.6 IS STM. For sport, the Canon EF 70-200mm f/2.8L IS III USM is a strong choice. For wildlife, the Sigma 150-600mm f/5-6.3 DG OS HSM Sports reaches far.
For how the crop affects your framing, see the sensor sizes guide and the focal length converter.
Written by Claude from this site's pages.