well done!! you'll enjoy Osaka so much, I'm looking forward to it soooo much too(*/ω\*)
so.. for the accomodation plan, please follow all is written in the email you've received, and I recommend to print (and also save as PDF in your phone as a copy) both the accomodation plan email, webpage and the lottery details.
The accomodation plan is made in 2 steps: at the check-in of the hotel they'll give you the extra goods of the accomodation plan, but for the tickets you have to line up at the entrance of the exhibition, where you can get your tickets.
Be sure to bring your credit/debit card you've used to make the payment, since they might ask it for a check.
For the lottery, I don't know what kind of email you might have received, but usually the lottery is a PDF of a A4 paper with barcode you can print and save into your phone and just show at 7eleven cashier (usually is 7eleven, it might be Lawson or Famima, it depends on what email you received, you'll see the logo of the conveninece store somewhere), they'll scan the barcode and print the ticket and give to you ^-^ you can do that as soon as you're in Japan ^-^
both the lottery ticket and accomodation plan should have included the exhibition entry ticket
the concert ticket has your name printed on it (in case of ID check) and the seat details, for example B41, it means B line/area - seat 41. each seat has the seat number printed on the back, so is easy to find it. doors open 1 hour before the concert starts, so you have plenty of time to find your seat and enjoy the waiting ^^ the concert hall is different from exhibition hall, so you have to exit and get into the line for the concert (you'll notice a staff member holding a sign at the end of the line), remember to wear the paper wrist strap they gave you for the re-entry
another thing I can recommend is to wear clothes in layer, because in the early morning and evening it'll be a bit cold outside the exhibition, but inside the venue it'll be ok, and during the live concert you might feel warmer and just wear the t-shirt ^-^
and if you have bought many goods, I recommend to put them in a coin locker (there are some inside Intex Osaka or at each train station) or in your hotel room, so you'll enjoy the exhibition and concert more comfortably. If you have, a backpack is also great for bringing goods, some snack and drinks ^-^ there are many restaurants and food shops inside Intex Osaka, as well as vending machines, but I also recommend to buy snacks and drinks before at a convenience store.
edit: this is a picture of Fukuoka tickets sales place near the entrance, notice the tables and the various signs, it'll be similar in Osaka, and for any doubts, you can ask and show your accomodation plan printed email and confirmation page to a staff member (they wear t-shirt with Staff printed on the back)
there are various tables because one is for accomodation plan ticket holders, one for general exhibition ticket sale, and one for press/others usually (●'◡'●)