Let me try (sure to reverse any progress you have made).
In the blue column you will see 1.74 in the FF row. This means that if you "buy" FF for 1 you will get 1.74 back if it wins including the return of your 1 stake. This implies the chances of a FF win as 1/1.74 = 57%. There is currently €17 on offer at this price. The overround % on offer is 101.2%. The closer this is to 100% the "fairer" the market. It is an exchange - you are dealing with another investor - the exchange (Betfair) takes 2% of any "winnings".
In the pink column there is 1.88 in the FF row with currently €43 bid. This means you can "sell" (or go short in the jargon) FF to receive 1 on the obligation to pay up 1.88 if it wins. The gap between 1.74 and 1.88 is a sort of bid/offer spread. Note that small is good. Labour is 1,000 because 1,000 is the highest bid/offer on Betfair. I will offer you 1,000,000.
The blue and pink columns are the currently most competitive with the other columns the less competitive offers/bids.
Try reading
@michaelm's post again after this lesson.
Warning: investments can fall as well as rise, indeed they can go to zero.