Metroid Prime's first form is kinda challenging to dodge, but still easy because of how little damage all of its attacks do. I can't dodge its really fast missile launch attack most of the time... and when it changes to white or yellow I usually have a really hard time doing damage to it. When it's yellow, the regular charge beam is too slow to hit it and it usually just hits an invulnerable part and bounces back toward me, so I just have to resort to rapid fire... When it's white, even the uncharged ice beam shots are very slow and often don't hit the weak spot unless I'm really up close... and when I'm up close, it likes to use that grapple attack where I don't know how to get out of it without getting hit other than getting lucky.
But even with all that, and with how long this first phase is, I still got through it while only taking about 2.5 energy tanks of damage... then when it gets to the 2nd phase, it becomes very easy. The only attack it has is an easy to dodge shockwave, and later when it summons Metroids out during the part where you can use the Phazon Beam on it, you can kill those metroids very quickly if you get to the Phazon before they grab you, or if not then just a quick power bomb to take care of them before going and getting as much damage onto MP as possible before the phazon disappears. Once you know the pattern of visor switching it always sticks to, this phase is much less annoying (although sometimes it can still screw you up when you need to turn into a ball to get rid of the small Metroids, and then you forget which visor to switch to).
Here's all the tokens I have currently after doing everything there is to do in Metroid Prime 1 Veteran Mode. Also before starting this I downloaded a save so that I'd have all 15 of the unobtainable green voucher tokens.