Many people who are new or lets face it even vets when it comes to kpop have trouble picking a bias. For me it comes pretty easy, im a very loyal person lol but really here are some tips!
The first person who catches your attetion always remind yourself that they got your attention FIRST for a reason!!
Its not easy to keep the same bias it really isn't so if you want to dont look at other kpop artist have tunnel vision! haha all joking aside and in all seriousness it's not a big deal to have more than one.
as for me mine has been v since their debut and he hasn't changed no one else has my attention like him lol sometimes you will just find one who will stick with you and leave a lasting impression and if you are lucky enough to have the same #1 bias then kudos to you!!
Also if it helps FYI there are different types of biases! !! so pick as many as you want :) bye for now -jojo