How can I start exporting and importing internationally?

This is a bit vague. Well to keep things simple I'll try to answer this question as straight as possible.

1. Find a manufacturer to provide you with products. Buy samples before placing a full order. Make sure to review all their licenses and certificates.
2. For small orders, international shipping carriers will do fine i.e. DHL, FEDEX, and UPS. This will get your products to your door as simple as possible.
3. Once you place a full order, you'll need to find a freight forwarding company. They will handle the logistics for large shipments that'll come in via sea usually.