hi hi!! ^u^
don't worry for that, you'll enjoy soo much! going alone, it'll be like a good adventure! hehe

if you have accomodation plan tickets, remember that you'll have to pick up the tickets at the entrance and need to show both passport and the credit/debit card used for the payment. But if you won the lottery ticket, then you just need to print (or save as pdf on your phone) the webpage with the barcode, then go to any 7eleven convenience store, show the barcode to the cashier and they'll print the ticket ^-^
There are staff people around the exhibition and in the concert venue, and when there is a long line (example, entrance line for the concert or long line for official goods shop), there is always a staff person at end of line holding a sign, so you know that is the end of line and you can go there. Also, for the goods, I know they accept credit/debit cards, but I always recommend to bring japanese yen cash too. At almost any shop you can also use the Suica contactless card (the card you use for the train/metro), which you can easily recharge with money at any station.
And like I said before, it is best to bring a small school backpack, so you can put it in some goods, drinks and snacks! and whenever you'll have many goods on your hands, it's better to exit the exhibition, put the goods in your hotel room or any coin locker around that train station, and go back to the exhibition (be sure to put the wrist strap they gave you at entrance so you can re-entry from the re-entry entrance).
Sendai is great and surely I recommend to stay a few days before, so you can explore the city, the beautful green parks, check some shops and restaurants. And about that rumour, mm.. is more like northern part of Japan is less used to tourists (compared to big cities like Tokyo, Osaka and Kyoto), so there are less english signs around, but you'll enjoy more because less crowded, and some shops/resturants staff might speak and have only japanese menu. But most of times, japanese menu have big pictures on it, so you can still order on it by pointing your finger on the food you'd like (say "kore to.. kore to.. kore to.. kore desu" which means "I'd like this, and.. this and.. this.. and this". This phrase is useful at the exhibition shops too!). Some restaurants, especially family restaurants, have "drink bar", it means for a fixed price usually around 300-500yen you can take how many drinks you want from the drink machine. I totally recommend to buy before a japanese phrasebook, like the one from Lonely Planet
https://shop.lonelyplanet.com/products/japanese-phrasebook-dictionary
and please check the important notices and fan guidelines, there's lots of useful info
Live show & exhibition connecting Hatsune Miku through creativity!
magicalmirai.com
Live show & exhibition connecting Hatsune Miku through creativity!
magicalmirai.com