Toil in SRE terms is a kind of work that is as quoted by Google, is the kind of work that is tied to running a production service that is intended to be manual, repetitive, tactical, automatable, and anything which lacks value, and that grows linearly with service growth. If you wish to master DevOps, which has a quite similar approach to software development lifecycle, then you must enroll in a good DevOps course from a reputed organization, which will help you in advancing in your career and will present more job prospects. I would also suggest you look into our YouTube video on DevOps vs SRE, which might help you get started with the training.