Can I have multiple buffs on 1 card?

No, a unit cannot have multiple buffs on one card, unless a specific card effect states otherwise.

According to Rule 702.3: "There can only be one Buff on a Unit at a time."

Additionally, Rule 702.3.a clarifies that if a buff is added or instructed to be added to a unit that already has a buff, it is not placed. This is also supported by the FAQ in the game rules: "A unit can only have one buff at a time unless a card specifically states otherwise."