It's important to not damage/seriously hurt your fingers. It's best to go slow, not push.

When I started playing again after a multi-decade break I had beginner's fingers. After a couple days of struggling through 30-minute sessions I changed to multiple ten-minute sessions, e.g., one in the morning, one in the afternoon. Things eventually got better as they always do with practice but I think the multiple short sessions toughened up my fingers faster than when I first started playing as a kid.

One has to press hard enough to make a note ring true... but no harder. If by 'very hard' you mean you are struggling to make the note sound cleanly consider having a guitar tech look at your instrument. A set-up or maybe different gauge strings might be warranted.

Good luck... have fun.