hackers at the door.

I hope this is the right forum for this issue.

overview:
It appears that I have several hackers attacking my Ubuntu server, I'm seeing ip address for overseas in the access.log and error.log in the Apache2 dir.
they are either accessing my private website or trying to run tmunblock or other GET functions.
I'm in the process of setting up a pfsense firewall, blocking all BUT USA mainland IP's, in the mean time, I've added these address' in the iptables. ( 213.0.0.0/8 etc...)
( I have a dynamic ip ( not static ) I only allow family to access this server. 10-15 people and if the IP changes, I email the new address to them.)

Question:
1) (security question) how do I tell or check if they(hackers) left a Trojan, spyware or something that will allow access to my server or broadcast it's ip to them? I intend to force the change of my IP to a new IP, and I what to be sure that they are not informed or have access thru spyware etc.., if it exist. (is there a virus/spyware scaer for Ubuntu?)
2) (general firewall question) should I block outbound traffic to all BUT USA IP's or would blocking the inbound be enough to prevent access to these hackers?

TIA

Tim