Possible transmission isuue

I would ask to see how the clutch pedal feels. If the pedal is feeling spongy or like it is sinking further than normal before you feel resistance, I would lean towards a clutch hydraulic concern. Check the hydraulic fluid level to see if it is low or not. If it is low, there must be a leak somewhere. The possible causes for a leak are the master cylinder, slave cylinder or the line between the two. One important note is that if the slave cylinder is leaking, it can contaminate the clutch surface and cause issues even after the leak is repaired so something to keep in mind. Here is a great resource on checking your clutch with a video for you to review as you need! Let us know if you need more help!

https://www.2carpros.com/articles/clutch-doesnt-work-sometimes-or-not-at-all

If it is difficult to shift into all gears, then it sounds like you may have a mechanical issue with the clutch. But a couple more things to mention since you identified first and second gears as the difficult ones to shift into or out of, if there was something wrong with the shift rail inside of the transmission then shifting through gears would be difficult even with the engine off. That is called a static shift test and if you are able to shift through all gears smoothly with the engine off, unlikely that there is a shift rail issue. If you are only having issues shifting into 1st and 2nd gear but all other gears are working normally, there is most likely a synchronizer or shift fork issue inside of the transmission. If it is difficult to shift into all gears and the clutch pedal feels good, has some free play and returns on its own/not spongy then the clutch will likely need replaced.