I've done a few similar outings with not too many surprises (well the ASI not working on one provided some unwelcome extra entertainment).
I'd suggest trying a bit of slow flying on your first flight - just short of actually stalling, to get used to the approach handling qualities and preparing yourself for a late go-around.
Also, if you build it yourself, don't risk making the aircraft's first flight your first on type too, that's the job of professional test pilots.