re: Will this be a learning experience for BK?

Kelly is not Orgeron. I doubt he designs a team on a year-to-year basis, I think he has a vision on building a perennial program.

He seems to have done ok with the QB situation here, as of now: he got a 6th year guy (Brennan) to come back and take reps in spring and summer, knowing Brennan could likely run those QB drills at this point.
He got a talented proven starter from elsewhere to transfer in, Daniels would have been the returning starter on a team that won 8 last year. This, despite neither Daniels nor Kelly having ties to LSU before the bowls last year.
He kept last year's QB prospect (Nuss) from entering the transfer portal.
He landed a highly recruited 5 star QB (Walker Howard).

Gonna guess Kelly considers this year as a transition, one where he puts his system in place and goes about restoring LSU's luster in CFB. Success won't be about championships this year, it will be about getting everything "ALIGNED". The goal will be to set it up so that LSU will be winning 10+ games minimum, every year, with a shot at the playoffs almost every year.