How to Start off
Ideally you need to start with an interesting fact or detail about you, your situation or your interests which makes you appear interesting and intelligent. You might also try a more general truth or saying, then show how this applies to your situation. You may want to quote someone famous who has said something relevant, but if so, keep it short, quote correctly, and make sure that the relevance to your position is absolutely clear. Don't quote for the sake of it.
Do give enough time to creating a good initial paragraph. It is the first thing your audience will read, and first impressions are quickly formed. If your first sentences are dull, irrelevant, eccentric or pompous, or worse still, full of grammatical or spelling mistakes, your reader will quickly form a negative impression which will be hard to dispel.