Good day.
My 98 Honda Civic DX (408K km) is getting increasingly hard to shift into 1st gear. 2nd can also be resistant but nowhere near as bad as 1st. All other gears are O.K. I have had a suggestion that a worn shift linkage might do this but wouldn't ALL the gears be difficult if that were the case? I'm afraid this is more likely a problem in the transmission itself.

 

How about reverse? If it also "grinds" trying to go into reverse with the car stopped, that would be a problem with the clutch.

 

I would make sure all the adjustments in the clutch mechanism are within the spec. If the clutch is dragging, it would make it hard to shift, I think. Also, I would check or replace transmission oil with proper grade oil and see if the situation improves.

These are required preventive maintenance from time to time anyways.

Good luck with your car.