Another general level 1 advice is not to strengthen your team too much. Just strengthen the team enough to win the league/Cup or whatever your goals are. Level 1 is a beautiful game where 3* players start with wages 1-2k, and they are fast trainers. This players should be your backbone over the next few seasons.

It is too easy to fill your squad with 5* close to 6* players, and you will probably win the league and the cup, but the consequences for season 2 is not good. You will be drawn into very hard league, champions league and especially cup. Whereas if your team quality is lower, your draws will be more favourable and with those fast trainers you can improve over the season.

An expensive highly starred player is not automatically the best performer. Stick to your good performers is my advice, and dont improve your team too much. Good luck!