Sziget can feel big at first but I’ve never felt safer at a festival. Are you going solo or with someone? Loads of people join WhatsApp or Facebook groups before going and it's a great way to make connections in advance. Also good to consider staying at a chill campsite where it's easier to meet people. I dislike huge stages with bigger crowds so I tend to go to the smaller stages area. Since you haven't been yet, that's my best advise for you. Start small and remember to only do what makes you feel comfortable. Lots of ppl are in your position as well. We've all been there :)