I have been using ebay for 11 years.
Ebay is individuals selling stuff yes people have stores and there are businesses as well.
Look at their feedback rating before you buy anything. If they negative feedback, you can click on the number and find out why and what the negative was about.
Read the item description thoroughly and ask ANY questions PRIOR to bidding.
Check shipping costs as well...some are really high...urgh...and that affected the good sellers because ebay changed their final value fees due to those bad apples!!!
You will have to have a Paypal account in order to shop on ebay. Paypal is safe and secure. Yes, people do try and phish and scam you - but in my 11 years I've not been scammed on ebay...
Craigslist is a different thing - luckily enough I've been smart/savvy enough to catch the scam before any damage happened.
GOOD LUCK!!!