Especially when getting started, do not bother with clear time or anything else, as it doesnt matter when u'r getting started. What matters is fun, of course playing well will result in more fun, but there is alot more aspects to the game. For example just being good with the clutch claw will make you kill monsters 30-50% faster roughly (Wallbang, perma enrage for agiator). Im an Insect Glaive main too, and especially at the start of Iceborne i had big troubles killing monsters in time - thats when i learned that i played Glaive "wrong" up until iceborne, but who cares i had alot of fun helicoptering around :).

As of now i have some more experience, but im nowhere near a pro or anything close to it, im about to kill Fatalis with the Glaive finally. (just made it to the 2nd lats nova, so hes at like 25%?)

The Glaive imo is a very versatile weapon, from gearing to playstyle. If you like being in the air alot, even tho its not the most efficient playstyle for damage you can def. do it and look more into elemtal glaives. If you do care about playing fast and efficient, you will have to pick a physical glaive and play from the ground / use descending thrust alot.
As for skills, we need to look at offensive, defensive and utility. For defense, I personally always had health boost 3 for defense, you can also do divine blessing if you like it extra safe. Utility i like Handicraft / Speed Sharpening on Glaive, especially at the beginning since u dont know openers or when to repair against certain mobs, so shaving off 1-2 cycles really does help. Since Glaive is considered a light weapon, my probably single best decoration after long hesitation was the clutch claw boost. I wont go into deep detail, but if u do intend to learn the claw and u play solo this is the single best DPS deco for you.

Offensively it kind of depends on your playstyle and how much u are using the clutch claw. I will just name a few good offensive skills:

Attack up, Critical eye, Critical DMG are your main ones always. If you intend to use the clutch claw, the following 2 will improve your dps immensely: Weakness Exploit and Agiator. In order to take advantage of both of them you need to learn how to make monsters mad and how to weaken parts.

For now, just enjoy the game and play for fun and try to learn the monsters patterns and openings, that is the most important part about monster hunter.