Ok, I can pick up and down, especially during a lot of strumming, but usually if I'm just picking individual strings, I pick up, and its really hard for me to pick down. Is anyone else like this? And should I go with it, or learn to pick individual strings down too? I mean I can alternate, but if I have to one or the other I pick up. So what should I do?
Do both. Usually when possible players like doing down strokes because it is easier to mute and to play dynamically.

But don't ask me, I like rap music.
try playing some scales slowly while alternating up-down strokes, it's just something you gotta practice to get good at
Alternating is important, so it's good that you're comfortable with up-strokes, but you should play slowly with down-strokes to get more used to them. Those should probably be your default - they give you better control and some techniques are only possible with down-strokes.
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