R4 new to all this

What is the best kernal ( i think it is called ) to use on a R4 I had gotten from alliexpress that was originally a 208 in 1 ds game cartage. I have been trying my best to work with it and add the games i want onto it but nothing seems to work.
First it gave me a black screen with the words " Loading..." in white on it, but it never when past the first screen. Please help