If you're active, support your games, train your players and watch videos for resources you can win trophies at the lower levels with a 4 star team. My second team is now at level 5. Won 3 league and cup doubles in the first 4 seasons. At the start of this season I had over 1300 rest packs, half of these have gone now as this season I've got lucky finding cheap (tokens) 18 year olds. I have also taken all my 4 star academy players and trained them to 100%. Paying 10 tokens for them was easier than fighting in the auctions.
My advice? Keep saving everything. Don't start spending until you have a season where you win nothing. And a 4 star team should be good enough for the first few levels.