For new players, it’s best to start with builds that scale well without expensive gear. Minion builds, totem builds, and spellcasters with good area damage are generally reliable. Since PoE 2 reworks many mechanics, community tools and updated guides on forums and sites like PoE Ninja or Reddit will be essential once the full game launches. Also, test builds during early acts to see what playstyle you enjoy most.
Not directly. PoE 2 is designed as a separate game with a fresh campaign, new gem systems, and class structures. While some concepts like elemental stacking or crit builds may carry over in spirit, most mechanics and synergies have changed. That means old builds will need to be reimagined to work within the new systems, and theorycrafting will be a big part of the PoE 2 experience.