It's not normal to have delays with Ryanair. They're actually quite punctual most of the time, and even if they have delays it is not usually their fault (it's Spanish or French air traffic control on strike, or bad weather). Ryanair operates very short turn-arounds, like other low cost carriers.
Can you sit anywhere on Ryanair?
Ryanair offers the option to purchase reserved seats or free seats, which are assigned randomly during check-in. Passengers who choose 'random seat allocation' can check in between 24 hours and 2 hours before the flight departure time.