Without access to RuneScape gold the Grand Exchange or trading, you'll need to collect and process everything yourself. Prioritizing early resource collection and skilling is critical.
Key Gathering Skills to Train:

Woodcutting & Firemaking: Chop logs to train Firemaking and unlock quests like Wintertodt. Aim for Willow logs early, and later Yew for Fletching.

Fishing & Cooking: Essential for generating your own food supply. Start with Shrimp, then move to Trout and Salmon in Barbarian Village.

Mining & Smithing: Craft your own armor and weapons. Start with Bronze and Iron, and move toward Steel and Mithril.

Crafting: Collect cowhides from cows in Lumbridge or near Al Kharid. Tanning and crafting leather armor boost both Crafting and combat readiness.

Runecrafting: Start with Air runes using the Rune Mysteries quest. This helps train early Magic and allows for basic combat spells.

Efficiently training gathering skills early ensures you're not constantly starving for materials down the road.

Early Combat Training: Start Smart

Combat is essential in OSRS, especially for Ironmen who can't rely on other players for protection or boss kills. The early game is your chance to build up a reliable combat base.
Recommended Low-Level Combat Targets:

Chickens & Cows: Chickens drop feathers and bones, and cows give hides for Crafting. Bury bones to RuneScape gold for sale train Prayer.