Government provided courses in Swedish as a foreign language for immigrants. Register for these as soon as you have your personnummer.
There are four levels, A-D, the most basic of which cater for those with little or no literacy in any language, and three speeds of learning. With a university degree and as a total beginner, you enter at the highest speed, at level C.
Classes at this level are either 6 (2x3hrs) or 15 (3x5hrs) hours a week, depending on whether you can attend in the day, or only evenings, and there are
Your progress is obviously down to your individual learning capability, but as a beginner at this level taking evening classes, to get to full fluency and graduate from level D usually takes just shy of a year.