Why do I need an escrow?
Not necessary, you should store your BTC in yourself

I thought trust was not needed it?
Terrible, pay BTC to any else where you do not trust, avoid it

Do I need a computer to store my wallet?
You can, but not necessary, a hard disk can replace it

What wallet should I use?
refer this https://bitcoin.org/en/choose-your-wallet

What is the common website where I can purchase goods?
Sorry, there are no common website, only overstock if it is

How can I accept bitcoin at my store?
You can use merchant tools by Coinbase, BitPay, and other exchange offered like LakeBTC

Where to create a bitcoin account?
No account with Bitcoin, only address and private. But you can create account at bitcoin website, e.g exchange, payment etc