I played my first (rapid) tournament recently and I wanted to calculate my ELO According to FIDE regulations I should calculate the average of my opponents and just plug it here: https://ratings.fide.com/calculator_rp.phtml. 
I scored 5/9 but a couple of players didn't have rapid rating so I don't know if I should count those players as 0 points of ELO or just calculate the avg without them. 
Also I don't understand the point 8.21 of the handbook:


  8.2 Determining the Rating 'Ru' in a given event of a previously unrated player.
  
  8.21 If an unrated player scores zero in his first event his score is disregarded.
    First determine the average rating of his competition 'Rc'.
  
  
    (a) In a Swiss or Team tournament: this is simply the average rating of his opponents.  
    
    (b) The results of both rated and unrated players in a round-robin tournament are taken into account. For unrated players, the average
    rating of the competition 'Rc' is also the tournament average 'Ra'
    determined as follows:
        (i) Determine the average rating of the rated players 'Rar'.
        (ii) Determine p for each of the rated players against all their opponents.
        Then determine dp for each of these players.
        Then determine the average of these dp = 'dpa'.
        (iii) 'n' is the number of opponents.
        Ra = Rar - dpa x n/(n+1)
  
  
  8.22 If he scores 50%, then Ru = Ra
  
  8.23 If he scores more than 50%, then Ru = Ra + 20 for each half point scored over 50%
  
  8.24 If he scores less than 50% in a Swiss or team tournament: Ru = Ra + dp
  
  8.25 If he scores less than 50% in a round-robin: Ru = Ra + dp x n/(n+1)


Should I calculate my 'Ru' using the average of the rating of my opponents, of the whole tournament or is it more complicated than that?

Thanks in advance.

Here are the games and opponents, I have only the 9 games I talked about so it might help: https://ratings.fide.com/chess_statistics.phtml?event2=&amp;event=1669320
OK, so the tournament was the Rattenberger Schnellschach-Open 2019 Tiroler Einzelmeisterschaft im Schnellschach It was a Swiss tournament. Here are your results from the tournament.

One of your opponents, Karl-Heinz Staudacher, has no rating. You should exclude your result against him altogether.

One of your opponents, Manuel Keßler, has a standard rating but no rapid rating. In the listing his standard rating has been used for pairing purposes and I believe this will also be used in rating calculations.

That means that you scored 4/8 against rated opposition. Accordingly (8.21a and 8.22) your rating will just be the average of those 8 opponents' ratings = 1885.5 which will be rounded up for display as 1886. If you play more FIDE rated rapid tournaments in June then the results from these tournaments will also be used in your calculations.


  I don't understand the point 8.21 of the handbook


This first says that if you score 0 in your first tournament then all your results in that tournament are excluded from the calculations. This is usually a good thing because it means that results which would give you a low rating (or no rating at all if it works out at below 1000) are not used. 

Coaches of weak players playing their first tournament and losing their first few games often advise the player to either lose the last game or two or to pull out of the tournament to take advantage of this rule.

The rest is just giving the rules for calculating rating in case of round robin and Swiss. Your tournament was Swiss so you should use those rules.