I am a little confused about interest. Can I take loan or even have a credit card?
We can of course take loan and also have a credit card. The Shari'ah has not dealt with the question of legality of using credit card. As for taking loan it is allowed expressly. There is no difference of opinion on that. As to paying interest to the lender we see that the Qur'an commands to those who had to receive interest from people to forego the money payable to them by way of interest. It did not ask the ones who owed interest to stop paying it. Besides the Qur'an used the words zulm for the act of extracting interest from the borrowers. The ones who were to pay it were referred to as yuslamoon (the ones being oppressed). This implies that the payers cannot be blamed.