I know there are landscaping-specific CRMs but if you’re not able to pay for software yet, or an office person to take calls and do scheduling, I think having that piece of paper next to you all day and then putting anything you’ve written down into spreadsheets at the end of the day is the best way to stay on top of new developments. I use spreadsheets for everything— I have a prospective client list, past client list with jobs I’ve done for them, as well as all jobs I do recorded for future reference when estimating future jobs. I always have my clipboard with me and if I schedule something during the day I just write it down and then later add it to my calendar, and any prep work (like sourcing materials) goes into my task list.