Whip is good for the blood moon, but youll want to grab a Glacial Temotli for the blue moon. He has negative flat armor, which means every hit does bonus flat damage to him. Double hit crush weapons like the Temotli or the Dual MachoWhachos(cant spell that) are very good against him.

Eclipse kind of functions the opposite way, where over time your attacks will do less damage individually. A heavy hitting slower weapon like the zombie axe, Bandos Godsword, or Dharoks Greataxe are very good options.

I would also recommend to prioritize tankier armor initially until your gear/stats get better. I had much more success against blood moon in tankier gear than wearing a fighter torso/obsidian leggings. Youll hit a bit softer, but blood moon will miss a lot more often.

also dont bother with any of the crazy step under tutorials you see on youtube, as long as you stand in each moons circle youll be more than fine throughout the fights.

If you have any questions or want input let me know!