How Long Do You Think It Should Take To Learn How To Sew From Basic Twice Per Week For Two Hours?

If you have learnt the basics, for example, how to do a overlocking stitch for the edges, and sewing seams, tapered and straight, plus heming, and you practice this for two hours a week, you would be ready after a month, to go onto more complicated things. Like button holes, collars and cuffs of a shirt, darts, zips and the rest.
Good sewing requires good planning and a lot of practice, before you can see really professional sewing. It also can not be rushed, as this usually results in a botched job.
You also need to know how to work off a pattern, which takes time and patience, as once you have cut the garment out, it is too late to go back, and start over.
As my mother, who was a good seamstress, used to say, "think twice, cut once".
If you persevere, you will soon be turning out things you can wear with pride.