Below 5k you cannot attack or be attacked.
5-20k you can only attack or be attacked by people half or double your own rep.
20k+ you will be a potential farm to the much higher rep people.
Too avoid becoming someones farm
Place your first subbase about 40 squares from your main.
Have enough transporters preferably Aerotransporters to transport all your resources.
Build a Basement high enough to protect the resources you generate overnight.
Before you log for the night or an extended period of time send all transporters and resources to your second base
To do this goto where your troops are stationed and press Send
Click TRANSPORT then select all your troops select the speed of their march so its roughly half as long as your going to be away, press send
Send all your troops on a transport mission but don't send any resources otherwise they will be in your second base for half the night.
Goto where your troops are stationed and press send
Click STATION then select all your transporters and resources(clicking on the number autofill's the box for you) select the speed of their march so its as long as your going to be away press send
This way there will be nothing at your bases and hopefully by the time you get back online your troops and resources should be arriving at your bases
Your troops will be back at your main so you can carry on doing expedtions,attacks etc
Resources will be at second base, build what's needed then send them back on the transporters this should only take 1-2.5 hours even using regular transporters
Reconnaissance(Increases the ability of reconnaissance and anti-reconnaissance of the scout.)
Go to tech center and research this. The higher it is, the harder for enemies to see what you have in your base.