Rebuilding your credit history takes months and even years.
There's no way to rebuild your credit history in a few days or even one month.
If you need to rebuild your credit you should contact any collection agencies and ask those collection agencies if you pay off those collections accounts if they will remove the negative remarks from your credit report.
If they say they will remove the negative remarks then pay those collection agencies off and if they don't want to remove the negative remarks then don't pay them as it won't help your credit.
You can then get a secured credit card through Capital One and put up a security deposit for the credit card which will be refunded back to you after you make on time payments and use the credit card responsibly.
The secured credit card will help to rebuild your credit and then you can take out other credit cards and loans to help build your credit rating even further as long as you make the payments to those credit cards and loans on time and don't default on them.
Expect it to take a year or more to fully rebuild your credit.