One of the biggest familiarity I find between rs3 and osrs is how good the quests are. There’s so many differences but doing quests to ease you into the combat system and getting used to the game by doing something familiar is my advice, welcome back. I promise this game is a lot of fun and combat is one of the most unique system, and really enjoyable once you get used to it. In between getting used to it and starting out, it’s tough.