2007 HONDA ACCORD TRANSMISSION?

I have a hard time changing gears into first, second, and reverse my clutch is fine, and works fine but I have a hard time getting into those gears… My clutch fluid is clean and full. Does anyone know what can be wrong? There's no leaking in the master cylinder and it is full.

Those are symptoms of a dragging clutch. How to know for sure? Check that you can shift into each of the gears with the engine off, then start the engine in neutral and keep the clutch depressed while trying each gear. If you have the problems with the lower gears, and grinding trying to get in reverse, the gearbox will have to be removed and the clutch replaced. Top suspects are a seized pilot bearing or a "popped spring" on the clutch disk. It is also possible the input shaft is rusty and hanging up on the disk but that is not so common as either of the others.

How does the pedal feel? Try bleeding the master and slave cylinder first. Check if the slave cylinder push rod is working. If the slave cylinder is adjustable, adjust it. Check the free play on the pedal. No joy, it is time to drop the transmission (transaxle) and inspect the clutch.