Is it supposed to be somewhat difficult to slide a stick into a gear?

Alright, so I'm fairly new at driving a stick shift, but I seem to have been having some difficulty sliding the stick from 1st to 2nd and 2nd to 3rd. Every now and then it'll be hard to throw it into 1st as well, but not near as much as 2nd and 3rd. I thought it was something on my end, so I focused and hammered the clutch, and tried to shift it nicely, and occasionally it works with limited to no problems, but usually it has some difficulty, and I don't want to force it into gear. Is it supposed to have slight resistant when trying to move the stick into gear? And if so, how come 4th and 5th gear don't have much resistant when I throw it into those gears? Also, if this is a problem… And since I caught it before it got to bad… How much would this usually cost a person to fix? I know the clutch is a pain to replace, so I hope it's not that. Also, while we're here. The clutch is really stiff, and somewhat hard to push down as well… Could that have something to do with it? Also, before you all say I don't push the clutch all the way in, believe me… I'm. So, any thoughts?

Added (1). Also, to add for the record… When the car is sitting in my driveway and turned off, it's easy to slide through the gears. So I know it's not the tranny.

Added (2). Also, on top of all these questions. I'm planning to change the oil in it as well and I'm curious which type of oil I should drop into it. I heard both 5w30 and 5w20 work well, but I want to know which one is the best for this particular vehicle. It's a 2001 V6 3.8L 5 speed Ford Mustang.

Alright, so I'm fairly new at driving a stick shift, but I seem to have been having some difficulty sliding the stick from 1st to 2nd and 2nd to 3rd. Every now and then it'll be hard to throw it into 1st as well, but not near as much as 2nd and 3rd. I thought it was something on my end, so I focused and hammered the clutch, and tried to shift it nicely, and occasionally it works with limited to no problems, but usually it has some difficulty, and I don't want to force it into gear. Is it supposed to have slight resistant when trying to move the stick into gear? And if so, how come 4th and 5th gear don't have much resistant when I throw it into those gears? Also, if this is a problem… And since I caught it before it got to bad… How much would this usually cost a person to fix? I know the clutch is a pain to replace, so I hope it's not that. Also, while we're here. The clutch is really stiff, and somewhat hard to push down as well… Could that have something to do with it? Also, before you all say I don't push the clutch all the way in, believe me… I'm. So, any thoughts? 4th and 5th gears have a higher ratio and are easier to mesh. But you didn't say what you drive… I have to think it's a hydraulic clutch. Clutch Pedal Freeplay is important. You shouldn't be able to wiggle the pedal more than 1 inch. It's also bad to have no freeplay. You can adjust the rod behind the pedal to get 3/4-1 in freeplay. Also make sure your transaxle is full of the correct fluid. Since it shifts good with the engine off, it confirms your shift linkage is good. You should check your Clutch Slave for leakage. NO. You're either missing the gate, or your clutch needs to be adjusted or repaired so it completely disengages. And yes, make sure you're pushing the pedal all the way to the floor with each shift.

Check the hydraulic fluid in the master cylinder if it has one.

Update answer: Then I suspect a clutch adjustment or repair is what you need. Clutch engagement or catch point needs to be adjusted. This or the synchros inside the transmission are severely worn from banging gears (power shifting)

NO. You're either missing the gate, or your clutch needs to be adjusted or repaired so it completely disengages. And yes, make sure you're pushing the pedal all the way to the floor with each shift.

Check the hydraulic fluid in the master cylinder if it has one.

Update answer: Then I suspect a clutch adjustment or repair is what you need.

Clutch engagement or catch point needs to be adjusted. This or the synchros inside the transmission are severely worn from banging gears (power shifting)