demo installation- multilingual

hi
i have a problem with demo installation. i saw other discusion and understood i have to contact to my web hosting and wants to increase memory limitation to 256 Mb ( what memory limitation is needed?)
if i can’t fix it , post it again.
but my problem is
when i was installing demo , images uploaded but no page post or slider upolad and install.
and in order to instruction {
Step 1 – Go to Tools > Import in your Dashboard.
Step 2 – Click on WordPress then Choose file and locate within the Fortuna package you unzipped: DemoData/fortuna.wordpress.2015-09-04.xml. Click Upload and Import.
etc. } run it again while you say { You should run the importer only once. Should any errors occur during the import…} . is this a problem??
my next question is important too.
i want to have a multilingual web site and i dont want to use WPML or any other plugin and want to install 3 wordpresss in one data base . my question is that i can install demo on 3 wordpress and i can have update for them ( i really dont know this question is true or not beacause this is first time i bought a permium theme and hear purchase code run in one wordpress)