It's all good mate we've all been there with the initial hesitation thinking this is all too good to be true :), and couldn't agree more the first couple days figuring out how to buy bitcoin and the wallets and all the terminology that goes along with it can be very frustrating, but all these feelings will quickly reside once your first pack comes through the letterbox i can assure you of that!
as far as buying bitcoin, i've used coinbase since day 1 (been buying 2 and a half years) they are a safe bet, fees are consistent, although consistently a little on the high end lol but manageable!
as far as having a seperate wallet, it's definitely the smartest way to go about it! can definitely vouch for exodus wallet! only needed customer support one time through my own fault and they were absolutely brilliant to deal with!
so you would buy your bitcoin from coinbase, send it to your personal wallet, and then you're good to go and purchase anything on here :) for ultimate peace of mind on your first order i would go for a vendor who offers special next day delivery with tracking! really puts the mind at ease imo
