1) Finish in the Top 7 in the league and your team gets promoted into next level league: top 4 gets you into the Champions League next season.

2) Condition is the players energy. When they do some activity (training or playing) they use condition and, afaik, the higher intensity the training or the more involved they are in a game or more 'motivated' they are in a game the more they lose. Green Rest kits replenish 15% condition (if used on 1 player) and normal rest recovers 5% every 3 hours. (You can also pay multiple kits to bring forward a 'whole team rest' (an extra rest).

Apart from that another way to manage it is to rotate players, only train once per day depending on number of games. Counting how many 3 hour intervals until the next game and multiplying by 5 (how much condition you regain) is a good way to keep an eye on things.