Prioritize Credit or Savings for first home?

[Robert Miciu]

Hello my name is Robert and I'm trying to become a real estate investor. I'm 20 years old and just started building my credit with a student credit card. Should I get 1 or 2 more credit cards and just build credit by using them for new mattress, rent ,etc or should I just focus on my one credit card line of 300 and save up for that 3% down-payment of a house?