You can't just send email to emails you got from another website's database or any other sources not explicitly signed up by the users, that is SPAM buddy!!
on the other hand, you can do a cold outreach campaign but seeing that you are new to this ,the probability of your emails landing in spam is 90%. To increase your chances, learn about warming up your sending emails, there a lot of tools out there to warm up albeit they are no cheap. Verify the emails to reduce bounce rate. if you need tools recommendations let me know
If I were you, I will rather gather my own list the right way, it slower, but worth and less expensive.