The tutorial forces you to buy a "Lesser Stalker" for 50 Soul Coins. Do not do it. Instead, use the "Barter" option. Offer your starting weapon (Rusty Pitchfork). You lose 2 attack power but save 50 coins. This single decision snowballs into buying a tier-3 demon by level 8.
Now that you're restarting City of Devils, here are some valuable tips to keep in mind: city devil restart guide