The car starts, but it is very hard to get it to go into gear.
The nature of this issue will depend on whether you have an automatic or manual transmission. If the vehicle has a manual transmission, the clutch master cylinder and slave cylinder would need to be checked, along with the shift linkage for binding and the pressure plate for warping. For an automatic transmission, the shift cable would be a likely candidate for failure along with the shift selector in the transmission. You may want to enlist the help of a mechanic, such as one from YourMechanic, to inspect the transmission to determine why the car is hard to shift.