Combine Lost Mine of Phandelver with Icespire and find the 4e Neverwinter city supplement, and you will have enough material easily for a 1st to 12th campaign.
That's kind of what I ended up doing.
I ran a group of total D&D noobs through a mashup of Dragon of Icespire Peak and Lost Mine of Phandelver. It went reasonably well and I'd recommend it as a solid sandbox. My total playtime was about 20 two hour sessions.
Once that was complete, about half the group fell out. The remaining players wanted to carry on. Some kept their existing characters, others made new characters. I relocated the campaign to Neverwinter. Conceptually, I thought of this as a spinoff series for a television show -- think The Mandalorian and The Book of Boba Fett. So I kept a loose connection to the previous adventures but mostly tried to focus on new material.
I'm sharing this story in case it's helpful to the OP.
The key thing about new players is to realize that most of them simply are not (and will never be) willing to put in the hours it takes to play in a campaign. Campaigns are a commitment from everyone involved. To get the most out of one, D&D has to be your primary hobby. Most players have other hobbies, interests, and demands on their time. With that in mind, I would suggest you do NOT run a campaign for noobs. Instead, run an adventure. If that works well, run another adventure. If that works well, run yet another adventure. Eventually, some players will leave, others will stay, and with those committed players in place you can finally begin a campaign.