When starting, clutch down 1st gear turning key truck jumps forward, will start but need to be ready to take off in gear that started in. starts fine in neutral.but won't go into gear without grinding

If it is manual transmission, turn the key on, hold clutch down, place in 1st gear, have someone push and then let go of the clutch. Be ready to push the clutch back in so the car doesnt cut off.

Clutch plate and pressure plate seem to be too weak to pull the car. Or one of the CV joints is detached from the gear box. To test the clutch plate, park the car on flat surface. Pull the hand brake up, start the car, depress the foot brake pedal, depress the clutch pedal, put the car in 1st gear, press the gas pedal and leave the clutch pedal at once, while keeping the brake pedal depressed.
Follow one of the two following statements:
1. Engine does not shut down and remain start. (Clutch plate, pressure plate and clutch bearing defective - Replace all as a set)
2. Engine shuts down. (Clutch system is OK and does not require any repair).

It sounds like you have a blown throw out bearing for the clutch operation. Fix it soon or you'll do a whole lot more damage to the drivetrain.

This may be due to a bad neutral safety switch, is this car automatic or manual transmission?

If automatic try to start in neutral and if manual try to locate switch on clutch pedal and use a jumper wire to jump connector for switch, NOTE; If switch is jumped car will start in gear with pedal not pushed down and car will take off so this is just as a test not a repair!!!!!, good day

your transmission gear sir maybe could have mechanical problem.

If the starter is shot no jump start should not work. The starter is what spins the motor.

Sounds like a clutch problem to me.
So, with the engine off, can you select all gears? If yes, your gearbox is probably OK.
And now with the engine idling, can you select any gears with out crunching? If this is difficult, then try this next test in an area where movement forward or backwards won't be a problem.
With the engine OFF, foot ON the clutch, the handbrake OFF, and in 1st gear, start the car. BE READY TO TURN IT OFF.
If the car moved forward as you cranked the engine, then your clutch is not adjusted properly or has worn out. That is more-than-likely the smell you got before - burnt clutch disc from it slipping.
You can drive it, but every time you want to start off, you'll have to turn the engine off, select 1st then start the engine. Accelerate slowly, making sure the revs don't rise faster that you're speeding up, and change gear by judging engine revs between gears.
Don't keep driving it as it is, as you WILL have gearbox problems if you don't fix the clutch.

What you describe sounds very much like the clutch is failing to disengage.
Fluid level being fine and no leaks under the car is good, but doesnt mean there isnt something wrong with either the master cylinder, slave cylinder, or the associated parts.

Highly unlikely there is a fault with the flywheel or clutch as failures with these would normally give no drive in any gear.

Heya,

Firs thing you can do to insure your clutch hasn't "gone" is start the car normally in gear. Obviously with your foot on the clutch. If it starts normally, your clutch is fine, if it jumps forward, it's your clutch.

Do you have any engine lights on?

sounds like the clutch isnt engaging at all...is there a different sound in engine rpm when car is at idle and the clutch is pressed and released? Check clutch cable.