Berserker gear provides unconditional power damage, since it supplies you with all three stats relevant for power damage and with the right main stat. Valk gear has been a pseudo-viable alternative for a while due to the trait Righteous Instincts, which provided 50% bonus crit chance while you had retaliation active.
Accessories are trinkets with two unique slots in the trinket section of hero panel 's equipment tab. Accessories provide the smallest attribute bonuses of the three types of trinkets, the other two being rings and amulets. For a comprehensive list, see list of accessories. An upgrade component can be applied to increase the characters attributes.
Tbh if you plan to learn raids your current gear is fine for training. Join Crossroad Inn Training discord and run with them. That way you learn the mechanics and earn raid currencies that can be exchanged for ascended gear in the aerodrom.Technically you don't need Ascended gear for anything aside from Fractals of the Mists, that set of exotic armor will do you just fine. It honestly doesn't matter what you level up, but I would recommend looking into what masteries you need for certain story bits (you don't need any for core, but Heart of Thorns and Path of Fire require some specific masteries to progress)
GW2. Ascended Guide. The complete guide on how to obtain ascended equipment. BEST Equipment and Gear up to date 2022. QSwGLD.