As resources and anything that gives your hero a bonus are all so essential in the early game, players that WOW Classic TBC Gold don't creep are at a massive disadvantage. There's the more traditional RTS base and army building, then there's the dungeon crawl/RPG aspect of fighting and levelling your hero, and obtaining some additional resources to help with the base. Nailing this multitasking is one of those game's most challenging aspects, but it's also why competitive Warcraft 3 is so unique.

If your hero isn't involved in combat with another player, they need to continually be creeping. Keep in mind, however, that once a hero reaches level five, they'll no longer gain experience from battling creeps.

You'll also find impartial buildings dotted around maps. The Goblin Laboratory, for example, can sell a Goblin Shredder, which is great for amassing substantial sums of lumber in a quick time. They also sell Goblin Zeppelins, making excellent scouts for recon. These impartial buildings are often guarded by creeps. If you happen to need something from a neutral building, but the levels of the creeps surrounding you're too high, consider awaiting nightfall. Creeps sleep at nighttime, so that you can rush in and rush out with no risk!

The first game in any match is all about efficiency and speed, as well as fielding the most effective units possible, whenever possible. With different buildings specializing in resources, tech trees, units, and defence, it is worth using a build order in mind so you don't get overwhelmed.

Much like heroes, it's hard to provide a definitive answer to what you ought to prioritise in your build order, since there's so many factors that could play into your overall strategy. That said, when you're first starting out, there are a number of generally agreed upon strings which are worth learning, if only to use them as a template for your own. Nailing the principles of aggressive Warcraft 3 has been a years long iterative procedure. You'll likely learn something new every single time you play, watch, or even read about a match. That said, these eleven year old forum posts for Humans, Orcs, Night Elf, and cheap Burning Crusade Classic Gold Undead are a fantastic place to start.