Welcome to the forums!
You can write down the payment dates in a notebook or in a spreadsheet. Check the notebook once a week. This way you'll not forget about your payment dates. You can also inform your family members about the payment dates. Tell them to remind you before the credit payment dates. You can even mark the payment dates on your calendar.
Marking the payment dates on your calender is certainly a good way of doing it. Alternatively you may prepare a list of such dates and apply a sticker to place it on your walls or over a furniture or equipment.
Use online banking. You can set up payment reminders or automatic payments.
Make use of your mobile phone. Set reminders and alarms on your payment dates so that you do not forget any date. You must be aware that the credit card companies charge outrageously high late fees that can unnecessarily add on to your monthly payments. There are various credit card companies that even charge a late fee for a payment that is even late for a minute or two.
So, take it seriously buddy and do the needful to avoid such credit card mistakes.