If you don’t have the credit you can just keep paying the balance as quickly as you need to from your cash accounts (once a week or once every few days). If you have the cash to pay for things, then you have the cash to pay for the credit used to pay for things.

Totally. To put it in programmer terms a credit card is really just a queue that has a penalty for keeping items in the queue too long. You can pay it off as often as you want. The size of the queue in that case isn’t as important. But once you have a larger queue, you have more time/convenience to pay it down.

The only way to build that credit is to begin using it. It takes time. My first card had a $500 limit. Now I regularly get 20k+ limits.