Apply on line to go to court? No you just turn up ( in the good old days you did) I think it’s 14 but just go and see when things get back to normal. Make sure you dress smartly. You cannot go to observe family court ( divorce) but my sons once went to Nottingham crown court to see a famous murder trial. A good idea would be to phone the courts themselves beforehand. It’s interesting to see both sides of the coin, the small cases and the more important ones.