1. Before starting mailings, especially transactional emails, you need to verify a sending domain. Add SPF, DKIM and DMARC records to the hosting site. This is required if you want to have good deliverability.
2. Add a domain to postmaster and track spam abuses, domain and IP reputation.
3. Test your email message text and the deliverability using mail-tester.com. Fix the issues if any.
4. Now you can start sending your first campaigns.
5. Sure thing you can use dedicated IP, but each new IP address as well as new sender domain need to be warmed up carefully. Start from sending 100-200 emails a day, then add a little bit each next day. Look through the statistics,
Don’t worry much about spam complaints if their percentage is rather small. I guess when you will prepare transactional campaigns, there will be 3 or more messages in email thread. Re-cover bounced and abused emails by sending second, third email, fourth emails to those recipients who opens the first message. If they open and read, they are loyal to your company, so you can continue communicate with them. And their opens and clicks will surely influence good to you as an email sender.