When I try to create the Virtual Machine using the FREE TRIAL, the Size option is telling me that a cost will apply. Shouldn’t this be free?
Azure doesn’t offer a "free trial". It requires a credit card and will bill you if you over-provision. New members get a $200 credit applied to your account. However, Azure services that are not free will tell you its costs. Then if you agree it will charge your credit before billing your credit card. Keep in mind the provided credit does expire, so even if you don’t use it all it may be removed from your account after X days.
Lastly, the free tier has limitations. e.g. Linux Virtual Machines 750 hours B1S VM.
The B1S is the size of VM you can provision. If you don’t provision this size it’s excluded from free-tier.
My recommendation is to have a basic understanding of Azure pricing before you actually start using it. Track your service credits and try to remain in the free tier if you are not trying to spend any money. As always clean up any resources in the cloud once you no longer need them. A lot of cloud services come with an hourly charge so forgetting to leave a service running for just 1 month can rack up a hefty fee.
VM at $0.10/hour 24 hours 31 days = $74.4
Azure allows you to set up billing alerts so you can be notified after spending X dollars and I highly recommend you do this as a first step on your account. Along with first steps should be to configure MFA so other people can’t hijack your account and rack up charges.