For people management, The Manager's Path by Camille Fournier is fantastic. That said, managing an offshore team (that also sounds junior) is going to create many headaches in addition to those you'll normally face as a first-time manager. Good luck!
Do you have to hire new devs for this? Sounds generic enough you can farm it out to any Shopify or WordPress/Woocommerce agency and probably get better results.
Ecommerce has a lot of intricacies, from the checkout flow to cross-site inventory management to CRM to product returns to transactional emails to order management to security and payments and PCI compliance, etc. It's a well established pattern that there are readymade providers and best practices for, but if you have no experience as a web dev and are working with a bunch of juniors who also have no experience... you might create a lot of footguns along the way.
If you're not going to do be doing the hiring... mate, I don't think you're in a spot to manage them.
Best thing you can do to help is set good requirements. Be clear up front. Have designs ready. Know how you want integrations to work. For off-shore teams especially, you need to have workflows, annotated wires, a style guide, and some sort of clickable prototypes to get the most out of the team.
You do all this mostly so you know where you need to provide copy, and so you know you're picking and choosing how all the integrations work.
As others have pointed out, there are nuances to eCommerce that can be tricky.
Some basics... (for pretty much any project these days)
1 - Make sure all code goes into a repository you control. Make sure there are no passwords in the code, and that you know how deployments work, and can build one (ideally on your local) if needed.
2 - Have them use Lighthouse. Aim for 90s in all categories or it's a fail. https://developer.chrome.com/docs/lighthouse/overview/
3 - Have them use Wave. If they can build a site without accessibility issues, odds are they know HTML / CSS fairly well. Aim for No Errors or Contrast Errors or a it's a fail. https://wave.webaim.org/
4 - Have them use HTTP Observatory from the start (just keeps everyone mindful about integrations and 3rd Party tools... updates to the Content Security Policy is another great way for you to make sure your architecture diagrams are in good shape. Aim for a B+ or it's a fail. https://developer.mozilla.org/en-US/observatory
5 - Make sure everything they use is open-source and permissively licensed, or you're comfortable paying for the license. A lot of times people will use some sort of proprietary accelerator, and the only real way to maintain a site built on those is to keep paying the people who wrote the tools... shady. Just be mindful for stuff like this -- the best way, I've found, is to make sure you are watching what all is used and how it's all licensed.
6 - Make sure you document things well, and assume devs will cycle off and on the project. Off-shore teams typically cycle through devs quickly, so you'll need a way to on-board new devs to the project quickly. Keep your architecture diagrams, and onboarding doc, coding standards updated. Make sure you have everyone's contact info; don't put up with anyone using a generic account, or handing an account off to someone else... best way to prevent being scammed with a bait and switch. "Oh here's the dev you'll be working with..." and then they switch him for someone less talented or who doesn't communicate after the first session... no thank you. Ha. 2FA on everything helps a bit. I always insist on doing a video calls with the devs when hiring 3rd Party devs... I hate doing it, but it just sort of keeps everyone honest.
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The Managers Path is mentioned earlier.
Can also recommend:
- The Art of Leadership by Michael Lopp (aka Rands of Rands in Repose fame)
Which tackles situations he encountered (and are all too familiar) while managing in various roles at Apple, Netscape and Slack.
- The Engineering Leader by Cate Hudson
What I think is absolutely great about this book is that it isn't just about how to deal with the people you are responsible for but also how to deal with _yourself_
- The Engineering Executive's Primer By Will Larson
This one is meant more for "Head of Engineering" types, but still contains tons of handy information to turn yourself into a effective leader.
And last but not least:
- Become an Effective Software Engineering Manager by James Stanier
Subtitle of this book says it all. Highly recommended!