Yeah, I found it very worrying too, having to physically go back into school after 4 months of not seeing anyone other than on teams. Maybe you could call your friends who you've been talking to over lockdown and catch up before you go back. They'll relate to the anxiety and you'll both be able to calm each other down. Also, think how everyone's in the same boat. You've all been in lockdown recently so you'll all feel a bit socially anxious. If you say this when you go back, it may make the conversations less awkward as people will be able to relate and you can bond over it.