You have several options to start a scan:
1. Go to the /assets page, add or select one or more assets, then press any of the ‘Scan with‘ buttons. You can scan using a pentest robot, using a scan template, or run a single Tool (scanner).
2. Go directly to the tool page (from the top menu TOOLS), enter the target, and press the ‘Start scan’ button. The target will be created automatically for you on the Targets page. Make sure you input the correct type of target for the scanner: hostname, URL, or IP.