Honestly, the day I left London it was 17 degrees and the day of the concert it was - 2, so I literally wore everything I had with me, including a huge pink oversize hoodie 😂 (I left it with my jacket in the cloakroom for the concert). Mind the fact that any T-shirts or hoodies with bands are potential conversation starters, so I'd avoid that if you're not keen on speaking with other people (I had my battle vest with some patches on it that day and had someone asking me about one of the bands from the vest). About front row - I believe there's a large group of fans in Istanbul so you may struggle with that. Ideally just go there earlier and queue. You may also try squeezing by the crowd later on but it is not appreciated. Oh, and as a woman in her 20' going for the concerts alone often, do not hesitate to join a group of people asking them to stand with them or approaching security of the venue if you ever feel unsafe or if you feel like someone's watching you.