I've been holding on doing any sort of questline in favor of waiting till I am level 46 so I can get the best Nightingale Equipment their is.

Problem is, I am only level 23 and I'm not what a good way to level up faster is. Trainers work good, but only training 5 times isn't helping me go up as much as I would like.

Any tips or advice?

What skills are you currently using?

Clear out dungeons.

Battle giants.

Smith things.

Enchant things.

Walk the roads, triggering random encounters.

Make potions.

Do side quests for NPCs.

By the time you are level 46 you have leveled your skills past what the Nightinggale armor gives. In other words, by Level 46, you don't need the armor, you already have the skills. The buffs are more important to a lower level character.

This. If your wanting it for the armor rating that's one thing but you won't benefit much from the enchantments on them by the time you reach lv 46