Even at gold 4 you are not going to be able to finish. You don't get enough energy for free. Plus, you would also have to win every match. And with the current invasion of whales, that spends hundreds and some thousands of dollars on these games, that's not going to happen.

You can't complete the event.

i think you should just stay at rank, where you can farm all arena tickets you get :) even if it's silver or gold 1 and 2

you get more points in gold 3 and 4, but if you can't win all arena tickets you get, you will still not get enought even to do half of the event and you will probably even loose on time and maybe some fights, so it's pointless to try getting somewhere, where you can't farm

tbh dont aim to complete the event, the rewards are not worth it for the amount of gems you have to spent for energy, just use it us a neat little bonus

Hi! Sure, you can use various opportunities to try and get all the listed rewards for the ongoing Arena event: buy tokens refills, move up the Arena tiers and earn more Medals, test different strategies for strengthening your current arena team, like refreshing their equipment, upgrading Skills etc (though, this part is one of the most challenging ones, of course) for winning more of the arena battles you participate in. I wish you the best of luck and hope you claim as many goodies as possible :) 

Laughable response, been playing since beta (5-6 months) and in 1 month have been surpassed by many of the whales.  Was able to complete the last arena event by burning some gems. Will be nowhere close to that this time.