Ebay & Ricardo either have things at a auction/ bidding level or a buy it now price.

I would attempt to give you some lessons on Ebay (not Ricardo as have a hard enough time myself with the languages).

With Ebay items at Auction have a finish time and date, whoever is the higher bidder usually is the winner.
With Ricardo, if there are bidders with similar prices, then it can go on further once the time finishes, not sure the time frames, maybe 10minutes each time, but believe only open to those who have already bid on the item.

1) Before I go further with Ebay do you have an Ebay Account?

Believe it takes a day or two to set up

2) how would you pay?

Many people set up a Paypal account and that takes several days to set up, due to the security for it.
As a buyer you can either link Paypal to a Credit card or your Bank Account.
As a Seller believe it has been to be linked to your Bank Account, but one can first be a buyer and later then later make changes to be a Seller

3) some items are for pick up only and then you pay cash, you would need to read the item description for this. Some items are listed for posting or pick up. If only listed for posting and you notice Seller is close to you, you would need to message them before bidding to ask if you could pick up if you won the Auction. For a number of reasons some Sellers do no allow pick up.
I like pick up as then one can check the item is as described, if not, then you walk away. It is the same if I am selling, if a buyer not happy they can walk away & I cancel the transaction so as not to pay the Ebay selling fees.

I will wait and see your response to when you have Ebay account and how you would pay