This is why it's important to be fiscally responsible and if you are in a good financial situation to take advantage of the system and use of credit cards.
Some basics you should do first is.
1. Budget
2. Track spending
3. Pay cc statements in full
4. If you are trying to optimize/improve your credit score, Ideally keep utilization under 10% with a maximum of 20-30%.
Assuming you can do all the above, excellent credit score and no plans to take a significant loan (i.e. home loan), I would then consider optimizing cash back and occasional churning. There has been some great cash back credit cards, but many have dissolved. Here are some good popular ones.
1. Chase Freedom - 5% rotating category; no annual fee
2. Discover It - 5% rotating category (10% for first year); no annual fee
*There are a 1-2 more (I think they still exist), so just research, but above two are most popular. Amex Blue Cash Preferred gives 6% at groceries, but $95 annual fee. If you spend tons, it may be worth it; do the math. Also Costco Citi is great too if you have a Costco membership.
For everyday purchases
1. Citi Double Cash - 2% CB; no annual fee
2. Chase Freedom Unlimited -1.5% points; no annual fee; sign-up bonus
*There are many other 1.5% CB cards, but I rate Ultimate Reward points from Chase much higher than 1:1 cash back.
I won't get into credit card churning or manufactured spending (MS) too much, but if you have no idea I would research. Checkout, reddit, flyertalk, etc. This is how you can a truly take advantage of credit cards. I personally don't waste time MS, but churn a few cc a year, especially since we travel a lot. For example last year was the Chase Sapphire Preferred card. My wife and I both got it and it's like free $3300 after meeting spending criteria (which we needed to do anyways for our upcoming vacation and stuff for our new home).