Don't bring more luggage than you can easily carry yourself. Bringing too much luggage (more than one large suitcase or two smaller ones) means you won't fit on the University coach. Even if you're travelling to Plymouth independently, it'll be difficult if you can't lift all your belongings on your own.
Travel with enough sterling currency (approximately £300) to cover your arrival expenses, travel, temporary accommodation etc. Bring the remainder of your money in travellers cheques, as a bank draft, or have it transferred after opening a UK current account. Bringing a bank draft or transferring your money? Remember it can take two to three weeks to set up a bank account, so bring enough money to support yourself until then.
The weather in south-west England is usually mild but changeable. It rains often, particularly in coastal locations, but we rarely experience extreme temperatures. The winter can feel quite cold, and occasionally there is snow. The summer is usually warmer (although it still rains!). Bring warm waterproof clothing, including a raincoat/jacket, umbrella and possibly waterproof footwear for the winter. Or you can easily buy these at a reasonable price once you've arrived.