Take tram no. 1 or 2 from the Swiss or French (SBB/SNCF) railway station; you will reach Basel Exhibition in 10 minutes. From the German Railway (DB) station (Badischer Bahnhof) you will be at "Messeplatz / Exhibition Square" in 5 minutes by tram no. 2 or 6.
If you stay in a hotel in Basel, you will receive the free Mobility-Ticket, which gives you unlimited use of all public transport in and around the city for the duration of your stay. When you check into the hotel, you will automatically be given a Mobility-Ticket. No waiting around or puzzling over vending machines – because you’ve got the Mobility-Ticket!