I'm surprised that nobody so far has given this advice to someone new to e-bikes.
If possible, buy your first emtb from somewhere local.
I know that "local" means different things depending upon where you live. But for me it means within less than one hour's drive, and preferably less. You don't want to have to face packing up the bike and posting it. You don't want to be faced with returning from a four-hour round trip to receive a text saying that your bike is now ready for collection! And even worse, upon arrival to collect it, finding that it hasn't been fixed after all!!!!!
That is just logistics. But the big benefit in having someone local is that they are easily on the end of a phone, with no foreign languages, incomprehensible accents or just general poor communication to deal with. Better still, when they are truly local, you can take your bike in and demonstrate the problem while they watch!
If you are an experienced biker, and used to doing your own work on the bike, then mechanical problems will hold no fears for you. But what about software problems, firmware issues, wiring difficulties (crushed wire anyone?), error codes, dodgy updates, motors bricking, charging problems........... (there's much more!) If you are unlucky, they will drive you to distraction. Especially when that intractable issue is fixed within minutes of arrival at the bike shop after a two-hour drive. Never be in a rush to set off back home after a long drive, insist that they take a first look straight away. Sometimes a software reset is all that may be required and that can take the time whilst you are having a coffee and a pee break before setting off back home.