Should i wear an ankle guard when i feel my ankle is going to give way or if it feels sore inside.

Sounds reasonable: Often a little compression wrap about the ankle will improve the symptoms and give you a sense of stability. If the pain persists see a doctor who may be able to give you a definitive diagnosis and treatment recommendation. Do you recall a specific injury?

Sounds like a good : Idea. So does seeing a foot/ankle doctor to figure out why it happens in the first place.

Yes: Yes, bracing is commonly recommended for "weak" ankles to avoid injury, but is recommend also physical therapy to strengthen your proprioception and ligament stability. Good luck!