Will hard pull affect my credit score even if I don’t currently have one?

You were probably denied for an unsecured card due to not having a credit history yet. You may have better luck starting with a secured card until you build up a history. (Search for "secured credit card cash back" to find some banks that offer them with rewards.)

Hard credit inquiries will slightly lower your credit score temporarily, and do not have long term effects. They are obviously needed though to obtain credit so don't worry about it in general. Just try to limit them to when you actually need credit. I don't know for sure how much they change your score when you don't have any history yet, but here is a general guideline for one FICO scoring model and how inquires affect your score.

Credit pulls only put a temporary ding on your credit. I wouldn't be concerned about it.

Don't worry as you've already mentioned that you don't have any credit history this may not affect you but in terms of building credit, you can begin with secured cards instead of applying for unsecured credit cards.

Hard inquiries aren't necessarily bad. They're simply an aspect of how credit reporting works. And it's actually good that this information is recorded. If you have a healthy credit history and credit score, to begin with, it's likely that any hard inquiry on your credit report would do very little damage to your score or even none at all.