I am older as well and just started playing osrs again after a long break. I have been slowly working on getting most of my skills up to around lvl 30. That’s around where the leveling slows down and things get a bit more grindy.

Also check out the optimal quest guide, I have been working my way through it and it’s a great way to get exp and unlock new skills, areas, and features. The quests are also adorable and memorable, my household regularly makes reference to “One Small Favour”. :)

https://oldschool.runescape.wiki/w/Optimal_quest_guide

Edit: Also, check out the Runelite client. It is a client to play rs in, and offers tons of quality of life fixes for the game. Some of my favourites are a graphics update making everything a bit prettier, and a weather plugin that gives dynamic weather. There are a ton of useful ones as well, for everything from inventory management to skill tracking.