I am biased as I have loved every last MH since Freedom. Every one of em.
Personally I do not think you would struggle with either game at the start. Since World, I think the Monster Hunter games have been far better about the on-boarding part of the game. With World the beginning is quite slow, as it helps you understand the loop, the game play, your options, the services in the hub, etc. Rise, personally, I felt had less hand-holding (not by a lot) but it is also quite easy in the beginning so you get some wiggle room in that way.
Rise is often called more 'arcade-y' by some. To me arcade-y is ... more like God Eater. I liked the style and characters in both game quite a bit.
Each brings a bit of unique aesthetic to the series, World and Rise. I'd say World can feel more realistic and though I hate to use the word, immersive. Rise feels faster, flashier, over the top to some. Rise is more colorful, different palette, more energetic compared to World's more weighty, rooted in the ground, world.
Depending on what you are playing them on, both can be had for quite a low price in places so perhaps that allows you to just... pick one and see?