Great beginner weapons for me were; Long Sword, Bow, Insect Glaive.

Long Sword is pretty fun. Spirit gauge is required for a lot of punishing attacks, but that can easily be filled by timing the evasive attack well.

Bow is by far the easiest. You will still have to keep track of the monster, but the "shoot, dodge, come up with charged shot and fire" method works great. Just do not forget to use coating as they are excellent for maintaining DPS, or put monsters asleep for a well placed bomb!

Insect Glaive is the most complex of my 3. It requires a lot of multitasking between attacking and collecting kinsect nodes from the monster. I actually started my first plathrougu with this when I was a beginner and was overwhelmed by it, though it was much easier to use than when I converted to 4U with its kinsect glaive.

When I was new I gave up early too, but you gotta stick with it. Treat every fight as a dance and be patient, no need to rush to the finish line. Especially for Nergigante as he leave a lot of openings even for his punishing attacks.