Is there a better option to rebuilding my credit rating? Or is that just something that will repair over time?

Hey I'm not sure if this is in the right sub-forum, I currently have poor credit rating as i rarely have any direct debits/contracts etc to come out of any account of mine, i also got myself into a bit of trouble with pay day loans when i was a bit younger and more gullible. I recently had a letter come through the post from Vanquis offering me a credit card with 39.9% APR. I've been considering getting a credit card recently and as the chances of the bank issuing me one is low, I wonder if this would be a viable option? Can a credit card help me rebuild my credit rating if i make all payments on time? I've also heard of this Aqua Card with the same APR. Or is this too risky? Thanks in advance of any response.