To start printing successfully, take time to learn and use PreForm software to setup each model and ensure a successful print.
Formlabs provides a thorough tutorial on the use of the Preform software that controls the Form1+ printer.
Unless you have specific support material or orientation requirements, we typically recommend using the One-click Print functionality of Preform.
One VERY useful technique for SLA printing is hollowing models to reduce material usage and print times. Download Meshmixer and follow this tutorial from Formlabs to easily produce hollow models.