trade the likely top 5 pick for a bunch of goodies this year. Gotta be 2019 draft goodies. Pick up an extra 2nd and 3rd or something to that effect. Or be like this year's Colts and have 18 picks in the second round (slight hyperbole).
Then, draft 2 WR, a center, a guard, and a RB (late, not until round 4 or later).
Round 1: WR
Round 2: WR
Round 2: LB/CB
Round 3: RB/WR/TE
Round 3: G/C (if value is there) otherwise LB or DB
This would give the team 2 (hopefully) solid rookie WR prospects, some OL help, and another offensive weapon in the RB or TE.
Then in free agency sign another mid-range WR (Golden Tate type player) and another OL.
Do all that, and if Allen is good this offense will be WAY different.