What can I do to improve my team?

[Arijanit]

Looks like I should cut it into questions to make it easier.

Is it okay to change/buy players often?
What's a good tactic to score as many goals as possible against a very weak team?
What's a good tactic to beat teams almost the same or a bit higher than you?
What are preferred settings/orders?

[George Triantafyllopoulos]

1 it's ok bro to buy and chance players often because when you promoted in another level all your players lose 1 star.so you should buy new players every season
2 i don't know very good tactics