Hi,What's the best way to make bulk updates to your inventory items? can i use a template and upload to make various changes or do i go in to each item manually?

go to gear>tools>import data and click products & services

there is a link for a sample excel file, use that

be very careful, this is QBO not desktop, if you mess something up there is no way to recover it, there is no back up or restore to yesterday.