Brace yourselves, I get to talk about a Miku concert! Sorry if it's boring to read, I'll try to keep it relatively short.
So, my only concert experience so far is Magical Mirai 2017. It's definitely something that I'll never forget. I had dreamed of going to a Miku concert for some time, and last year was the first time it was possible. It had such a huge impact on me and I enjoyed the experience so much. And not just the concert; the exhibition had lots of cool stuff to see and do.
Of course the concerts were the highlight of Magical Mirai. Over the course of 3 days I attended 4 shows. While I didn't manage to get the more desirable SS tickets (I only got S for all shows) I was still extremely happy to just be there. The concerts were an experience like no other. Seeing your beloved Miku and other Cryptonloids on stage with a live band, cheering for them with thousands of other fans, singing along etc. was just amazing.
Also the feeling you get from the collective energy of the audience is something hard to describe. I mean, you're there with thousands of other fans, you share the same passion and dedication. Other members of the audience are strangers, but you still feel united in a way. United by love and appreciation towards Miku. A good example of this was after the Sunday night show when it took quite long for the audience to leave. People were enjoying the after concert atmosphere and when fans slowly make their way out from the premises, people would randomly burst to cheers and Miku-chants. Some random Japanese fans came to me to shake hands, giving high-fives and stuff and chatting.
The Sunday night concert had the best atmosphere by far. As it was Magical Mirai 2017's last show, people were super hyped and the cheers had more power and emotion than in the previous shows.
It's actually hard to point out something I didn't like. Maybe the downside of the event was long queues everywhere. On the first day of Mirai, Friday, I first lined up to get my tickets, then join another queue to enter the exhibition (after getting the tickets, it took more than an hour to get in). Once I got in, I obviously had to go and grab official goods while they last. Lining up for the goods took around 3 hours, I can't actually remember. And of course some of the stuff I wanted was sold out when I finally got to the counter.
One small problem was also the fact that it was my first Miku concert and first concert in Japan so I wasn't sure of stuff like which line to take to pick up my tickets and stuff. The Makuhari Messe staff of course doesn't speak English and English signage was scarce, and I'm not good with kanji or quite fluent in Japanese. But it all worked out just fine in the end, so it wasn't really a problem.
I'm sure you'll have the time of your life at Miku Expo, especially since it's your first Miku concert. Your first concert experience will surely be something you will always remember.
Some tips: Have a bottle of water with you, go to the venue early enough (to avoid the stress of hurrying or being late), mind your manners and take others into consideration. Above all have fun! You'll enjoy it a lot, I'm sure^^
but as long as I've done it once, I can be happy with that. I hope you really have the best best time!!