You can get insurance that covers you to ride a bike you can't ride through - bikesure.. so you have to agree not to go on a public road - unless under instruction. They will insure you for a max of 60 days (for me it was £50 for 1 day and £98 for a month, so worth asking how much it i for longer in case you need to resit.).
For a Mod1 or Mod 2 test - your 'trainer' is the examiner. IYSWIM. But you would either need a friend to ride the bike to the test center -or trailer it there.
You will need to do your Mod 1 - on the same 'level' of bike as a Mod 2. (so you can't do mod 1 on a 125 and a mod 2 on a 650 for example).