I'm trying to make a v2 profile and I'm looking at someone's for ideas. I was wondering what some of these codes are and do I need them in the code.

Header:
#header_left img {display: none;}
#header_left {margin-top: 13px; margin-left: -0px; width: 500px; text-align: right; font: 8px Felix Titling; text-transform: uppercase; letter-spacing: 1px; color: #f8f8f6;}
#header_left a {color: #b3c1ae;}
#header_left a:hover {color: #fffeb1; text-decoration: none;}
#header_right {margin-top: 13px; margin-right: 75px; width: 245px; text-align: right; font: 8px Felix Titling; text-transform: uppercase; letter-spacing: 1px; color: #f8f8f6;}
#header_right a {color: #b3c1ae;}


Columns:
#columns {background: url(Continuation IMG) top center repeat-y;}

#column_1 {width: 511px; background: transparent; margin-left: 22px; margin-right: -22px; overflow: hidden;}
#column_2 {width: 245px; background: transparent; overflow: hidden;}
#column_3 {width: 800px; height: 117px; background: #b3c1ae url(Footer IMG) top center no-repeat;}
#column_3 .panel {display: none;}


Panels
.panel {background: none; margin-bottom: -0px; margin: 0px auto;}

#column_1 h2 {font-family: "Felix Titling", "Trebuchet MS", serif; font-size: 12pt; color: #f8f8f6; text-align: right; background: #ccd2aa; font-weight: bold; border-bottom: #fffeb1 2px dotted; height: 18px; letter-spacing:1px; padding-top: 10px; margin: 10px}
#column_1 h2:first-letter {font-style: none; font-family: "Felix Titling", "Trebuchet MS", serif; font-size: 16pt; color: #b3c1ae}
#column_2 h2 {font-family: "Felix Titling", "Trebuchet MS", serif; font-size: 12pt; color: #f8f8f6; text-align: right; background: #ccd2aa; font-weight: bold; border-bottom: #fffeb1 2px dotted; height: 18px; letter-spacing:1px; padding-top: 10px; margin: 10px}
#column_2 h2:first-letter {font-style: none; font-family: "Felix Titling", "Trebuchet MS", serif; font-size: 16pt; color: #b3c1ae}


Column Font Colors:
#column_1 .panel {color: #ffffff;}
#column_2 .panel {color: #ffffff;}
#column_1 a {color: #ffffff;}
#column_2 a {color: #fffeb1;}


User Info Buttons:
#user_info {background: #ffffff; border: #ffffff 1px solid;}
#user_info li{border-top: 1px solid #ffffff;}
#user_info a {color: #fff;}


Comments:
#column_1 .comments_panel .style1 dt {border-bottom: 1px #fff solid;}

.comments_panel .avatar {display: yes;}
.comments_panel .style1 dd p {margin-left: 0px; text-align: left;}


I have learned about some of these, but for some, I haven't and was wondering if I need them in my code. Thank you!