I would start doing all the basic lifts free weight. The sooner you start doing it right the further ahead you'll be.
Your body learns how to cheat on those machines. Anyone who tries a smith machine for a few weeks learns how to "ride the rails". You can basically do a decline press (which is stronger) and let the rails glide it up. When you go back to free weight you have gained little or nothing. You won't benefit your stabilizers etc. Squats are even worse on that machine. I often train squats by my self with no problems.
I hear the same kind of question about half-squats. Guys don't want to stop doing their "big weights", and back off to do things properly. If you start from a light weight, learn it properly, and hit full depth, your progress will be faster in the end. Soon you will pass your old weight, but be doing it right.
Start with one plate per side. Squat with precision. Focus on tension and control. Get your form written in stone. Don't be sloppy because a weight is light (focus even with the bare bar). Do many sets of low reps, this will force you to practice setup/walk out etc. Let the weight come later when the form is nailed.
can u list some of ur reason why smith squats are more dangerous then reg squats?