Upgrade Magento from 2.3.3 to 2.4.1

I am running magento 2.3.3 and i want to upgrade to 2.4 or 2.4.1 there are a few small glitches in my site that i hope this will correct. i tried doing it view the wizard but it was failing. need to update composer and possible some other setup requirements? also my cron jobs are not set up properly for my site.