Can multiple sclerosis start with a feeling of tightness in the lower leg, pressure and weight on the lower leg only when walking , how common is this initial symptom?

What you describe is very unlikely the initial symptom of MS. By the way, what is the reason you think of this debilitated condition in the first place? Take care.

If the "feeling of tightness" represents clinical spasticity in both legs, then this could correlate with spinal cord pathology. Your posted description suggests that this is unlikely a presentation of a neurological disorder. Since the multiple in MS represents more than one lesion, you would not fulfill this diagnosis regardless. Have a podiatric consultation to check this out further.