What's the main benefit you're looking for?
Essential oils have helped me with so many things...for example - first aid, skin care, pain, and as antibacterial and anrivirus agents etc.
A good one to start with is peppermint. I find it energizing and it clears the sinuses. A dab on the temples has helped make my headache go away.
Then there's clove which I used on my gums to numb pain after dental surgery.
I rely on my intuition when I'm not sure which one to reach for. Today my favorite is hyssop.
I'm pretty sure the oils were the smelling salts of old... And maybe even what Aladdin had in his magic lamp.
Just try to buy quality. I use a couple of different brands - the best I can find... I hope this helps!