online assessment

i just recieved a letter saying im being offered an nhs online assessment for autism.  i thought i would have to attend their office for my assessment but the letter says an online assessment video call, then one face to face appointment after that.  can anyone tell me if they had an online assessment and what was it like. also can i have notes with me about my issues because i have a bad memory and anxiety depression.  i have no family member to be with me but my social worker said she will be there.