Clash-of-clans – I set up new clan but accidentally left it. No other players in the clan yet. Can I recover it

Until you reach Town Hall 5, 20% from your gold/elixir can be stolen from the storages. The cap for this is 200k. From TH6 and onwards, this percentage drops by 2% for each TH level. From TH7 and above the cap increases with 50k for each TH level.

So for clarity and completeness (and no calculations):

TH Level    % Available to be Stolen    Cap    Storage Amount to Reach Cap
1-5         20%                         200k   1.000M
6           18%                         200k   1.1111M
7           16%                         250k   1.5625M
8           14%                         300k   2.1428M
9           12%                         350k   2.9167M
10          10%                         400k   4.0000M

Well I don't think that you have many options. You can try to contact the developers and try to get them to set you back into the clan. But I would bet, they won't do.

Instead you can create a new clan and invite your old fellows and start over again.