You can import your emails, contacts, calendars, tasks, notes, journals, etc from old computer Outlook OST file to your new PC by converting it to PST format and then directly import the PST file in the MS Outlook application installed in your new your Windows or Mac computer.
To convert OST to PST file you can use vMail OST to PST Converter Tool for a safe and quick ost to pst conversion without any risk of data loss. This is a third-party email converter software for Outlook data files. This OST file converter can convert OST file to other formats like MSG, MBOX, EML, EMLX, HTML, PDF, RTF, formats and also perform cloud migration from OST to Office 365 and G Suite.
Software Link - OST to PST Converter