SQL & PL/SQL

I am trying to connect to my database using iSQL Plus. The database is the default from installing 10g. I renamed it "database" and put the password as password.

Per instructions, I created some kind of loop for the DHCP..and the database installed correctly.

I have both the database installed and the 10g developer suite installed.

I am very new and naive to all of this stuff. I'm currently taking a database class which uses this software, and I need to be able to do this from home because I can't get to school to do it during lab hours.

So..when logging into iSQL Plus I am trying to log in with:

Username: system
Password: password
Host String: acerlaptop
acerlaptop is my computer name, and per instructions, this is what I thought I was supposed to be putting in for this...

I am receiving this message after trying to log in:

ORA-12514: TNS: listener could not resolve SERVICE_NAME given in connect descriptor
I have also tried these variations for the Host String:

//acerlaptop.:5560
//acerlaptop.:5560/database
acerlaptop/database

among others. I haven't a clue what to do, where to go..I am completely new to this software, except the very little exposure I've had at school. I have now spent 6 hours trying to install this software, when all I want to do is the darn exercises in my textbook...

PLEASE HELP ME! My assignment is due on Wednesday!!!!