Starting with Gymnasium in Sweden

I hope I will be able to start schooling in Sweden in the 1st year of gymnasium. The problem is that I don't yet have the level of proficiency needed to go to school, I'm still learning and will be able to
speak Swedish somewhat by the start of the next school year. Do you think that my everyday knowledge will be enough to start schooling, and if not what level would I need to start going to school? I can attend my school in Serbia online but would not like to do that because it will only delay my Swedish knowledge. My parents are for the decision to attend school online for the first year in Sweden so I don't lose a year. I would like to attend physics or engineering in gymnasium. What is your advice?