How to justify text

Do you mean this text: Rent Lake Como SRL …
i guess you have inserted it by copy and paste from maybe a word doc ? there is no p tag in that pasted text. it is in a span tag.

so if you don’t want to influence all avia_textblocks (team element etc) with:

#top.page-id-460 .avia_textblock {
    text-align: justify !important;
}

you have to edit this text-block and copy paste into the text not the visual editor mode, to have there p-tags.

by the way : justified text can be very ugly – to avoid this there is a nice multilingual plugin called hyphenator.

this is what you have inserted i guess via copy/paste on the text:
so you need to edit that first

<div class="template-page content  av-content-full alpha units">
<div class="post-entry post-entry-type-page post-entry-460">
<div class="entry-content-wrapper clearfix"><section class="av_textblock_section ">
<div class="avia_textblock  av_inherit_color ">
<div>
<div class="WordSection1">
<div class=""><span class="" lang="EN-US">Rent Lake Como SRL was created to provide high quality rental international services in the Lake Como area.</span></div>
<div class=""><span class="" lang="EN-US">From apartment or villa rent to particular requests you may have during your holiday, we cover them all.</span></div>
<div class=""><span class="" lang="EN-US">A young, experienced and creative team is responsible for your comfortable vacation.</span></div>
</div>
</div>
<div>
<div class="WordSection1">
<div class=""><span class="" lang="EN-US">We believe that renting a villa or an apartment is a much better value than a hotel room, as it gives you more space for the same price or cheaper and you live like a local or as if you were home. Plus, you have the convenience of an experienced concierge like ours, who can give you any service you need. Enjoy your stay and feel free to contact us anytime.</span></div>
</div>
</div>
</div>
</section></div>
</div>
</div>

try then :

#top.page-id-460  {
    text-align: justify !important;
}