First Credit Card?

Hi guys.

I am with Natwest as my bank and I have just had my current account converted to a student account and I have also applied for the £2000 overdraft as one of the benefits that come with the student account. So firstly, will I have been credit checked for this, and does this mean I should wait a week before applying for a credit card?

Onto the credit card itself - I am not sure what to do first. I am highly attracted to the aqua Reward credit card with 0.5% cashback, as since it is aqua they are more likely to accept me. But the thing is with Natwest they offer the student credit card and has one of the lowest interest rates for someone starting on credit at 18.9%, though the eligibility checker tells me I'm unlikely to be accepted which surprises me given I am supposed to be a student and have limited credit history. I was thinking it might be an idea to start with the aqua card to better my credit then maybe get the Natwest for low interest somewhere down the line? Obviously I'm aiming not to pay a penny of interest lol, for the record.

Thanks for reading and feel free to let me know what you guys think!