I don't know how realistic that is, but if you're going to try this, I'd recommend the following: as a prerequisite for your doing this they have to permit you

I don't know how realistic that is, but if you're going to try this, I'd recommend the following: as a prerequisite for your doing this they have to permit you to straight off the bat recruit two people internally from the existing sysadmin team. One should be someone with a deep understanding of the bare metal networking, security, etc. concerns, who's enthusiastic about learning how that translates to an AWS environment. S/he will advise you to make sure you get that part right, and hopefully pick up enough to pitch in to design and build your infrastructure. The other should be someone with a strong understanding of the old bash scripting who's interested in learning modern devops scripting. They'll help you translate the old scripts to new paradigms and eventually help you build out the rest. Both of these people will have to be fast learners willing to spend the first month or so learning the essentials. Make sure you have funding from management to support whatever video tutorials, online courses, etc. they need to get up to speed.