Planned spending of around $100K-$200K/month on online shopping. How to maximize cash-back?

• Current cards:

  • Venmo $8,000 limit, Jan 2025

• FICO score: 804

• Oldest account age: Among accounts I actually opened myself, about a week; I think my mom signed me onto her card about 2 years ago.

• Chase 5/24 status: 1/24

• Income: Around $500,000/year

• Average monthly spend and categories: I'm not positive but I travel a lot for my work which incurs thousands in gas costs, and I probably will wind up spending $100K-$200K/month in "online shopping"

• Open to business cards: Yes

• What's the purpose of your next card? Cashback

• Do you have any cards you've been looking at? American Express Blue Cash Unlimited, Bank of America Cash Rewards

• Are you OK with category spending or do you want a general spending card? Yes, I'm okay with category spending.

I've never had a credit card before, except my mom put my name on several of her cards 2 years ago (JPMCB and PNC Bank, according to a credit report). I applied for Venmo's credit card as it offers 3% cashback, but my credit limit is only $8,000. I don't have any other credit cards. What are the credit cards I should try to get to optimize cash-back?