Run at least four times per week. A consistent running routine increases endurance because your muscles train themselves to perform repetitive motions more efficiently. Running every other day is adequate to build this muscle memory. A run can be of any length, and beginners should start with runs no longer than 10-15 minutes.
Keep track of what you have been doing, and what is working for you. Evaluate what exercises you enjoy and what left you bored. A fitness plan should never be stagnant. Keep switching things up and changing things that aren't working for you. A fitness plan that is set in stone is a fitness plan you'll stop using.