You would use a new database for each install
if you wanted to call the same data for each website you could use one database but i am assuming thats not the case so go for one database per website
its usually yourdomainname.com/cpanel
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What type of form is it?
Is it a contact form?
Why not use a plugin like contact form 7
?
Does that help?
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Unzip the folder first and just check there isnt another zipped folder inside
sometimes there is as there could also be a manual and psd files in there too
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