Hi,

If you want use mail chimp on home page, please use mailchimp shortcode then choose style you want 

http://prntscr.com/p41j9n

If you want use Newsletter on header and footer, please go to Dashboard > Appearance > Widgets then add mailchimp  widget on header and footer

Custom css

.penci_dis_padding_bw .penci-mailchimp.mailchimp_style-2 .mc4wp-form > form > p:last-of-type,.penci_dis_padding_bw .penci-mailchimp.mailchimp_style-2 .mc4wp-form .mc4wp-form-fields > p:last-of-type {
    margin-bottom: 0
}
.penci-mailchimp.mailchimp_style-2 .mc4wp-form {
    margin-left: auto;
    margin-right: auto;
    text-align: center
}
.penci-mailchimp.mailchimp_style-2 .mc4wp-form .mdes {
    font-size: 18px;
    font-style: italic;
    line-height: 1.5;
    max-width: 720px;
    display: block;
    clear: both;
    text-align: center;
    margin-bottom: 23px;
    margin-left: auto;
    margin-right: auto
}
.penci-mailchimp.mailchimp_style-2 .mc4wp-form .mname {
    display: none
}
.penci-mailchimp.mailchimp_style-2 .mc4wp-form .memail {
    display: inline-block;
    width: 100%;
    max-width: 390px
}
.penci-mailchimp.mailchimp_style-2 .mc4wp-form .msubmit {
    display: inline-block;
    width: 140px;
    margin-left: 10px
}
.penci-mailchimp.mailchimp_style-2 .mc4wp-form input[type="email"] {
    background: none;
    border-radius: 0;
    transition: all .3s;
    -webkit-transition: all .3s;
    -moz-transition: all .3s;
    padding-top: 0;
    padding-bottom: 0;
    height: 48px;
    line-height: 48px;
    font-size: 14px;
    margin: 0;
    max-width: 400px
}
.penci-mailchimp.mailchimp_style-2 .mc4wp-form input[type="submit"] {
    border-radius: 0;
    height: 48px;
    line-height: 48px;
    padding: 0
}

Best Regards,
PenciDesign