Given that this first week of the season is a short week with only a scrimmage and you have two draftees you want to train, 1v1 forwards is a safe starting point. Within a week (before next training update), I would guess that a U21 scout will have contacted you and you guys can discuss a longer-term plan moving forward. But when in doubt, it's hard to go wrong starting off with either some 1v1 forwards for elastic effect or pressure for the most important skill in the game.