RE: First-time kit to build?
A trainer is more than a flying trainer. Kits like the Sig LT-40 and the Goldberg Eagle are geared for the first - time builder. You might try building a trainer kit, for that reason.
A Sig Someth'n Extra is very easy to build, as are all the Herr offerings. There are certainly others. Most more advanced kits are short on hints for the first time builder - or completely devoid of them.
Good luck, and welcome aboard,
Dave Olson