This has been answered numerous times by the community and by SEGA in various videos. The best guide exists on the PSO2NGS subreddit's Wiki: https://www.reddit.com/r/PSO2NGS/wiki/faq#wiki_what_can_i_bring_with_me_from_pso2_to_pso2.3Angs.3F
To sum up:
Not Coming Over: Skill Rings, Boost Consumables, Materials, Room Furnishings, Any Currency outside of AC and SG, and your Inventory (Vanilla and New Genesis use separate inventories).
Coming Over, but heavily changed: Weapons and Units, just with different stats, affixes, and potentials. Units are invisible on Halpha (New Genesis) and visible on the ARKS Ship (Vanilla). Mags will be a cosmetic option - not providing stats or combat assistance.
Coming Over, but not modified: Outerwear, Outfits, CAST Parts, Weapon Camos, Salon/Character Creation Cosmos (Basewear, Innerwear, Body Paint, Hair, Accessories, Emotes, Voice... etc).
Fashion brought over from Vanilla will use the Vanilla models - meaning no Finger Movements. If you want finger movements, you will have to rely off of the New Genesis models. However, that will be the best ting ever, seeing as New Genesis models come with more customizability than Vanilla ones - Neuman/Deuman options are merely parts that can be added on at creation. Additionally, items released for PSO2NGS will carry back all customization when playing Vanilla.