What to wear to a concert ?!

[PollyannaWhittier]

I'm going to see Bonnie Tyler at Indigo at the O2 in July and I don't know what to wear !
I'm 30, 5'5", size 12 and I've never been to a concert before
Help !

Whatever you would wear to go to a pub with friends on a Saturday night. Basically normal, everyday clothes.

Jeans & tshirt

Whatever you are comfortable in. You don’t need to dress up.

Literally nobody cares. Whatever you usually wear. Nobody is looking.

Jeans and T-shirt
Denim skirt and t-shirt
Anything you feel comfortable/good in, have a great night.

Thank you for the replies. I have quite bad social anxiety and this is a massive thing for me, I'm terrified and trying not to get anything wrong.
I'm normally in walking trousers and a fleece when I'm not at work, but I can do jeans and a t-shirt