And what D&D campaign has you fighting fiends and intellect devourers at level 1 without even prepping for an adventure? I think the bigger problem is that the story describes your party members as being adventurers with renown such as Will (Level 2) and Gale which are seasoned adventurers or wizards in Gales respect. These characters would not be level 1 in a D&D campaign.
As was pointed out by Zyr, these are CR 1-2 creatures that you're upset we end up fighting at level 1-2.
Gale and Wyll also both talk about having lost powers recently. A once mighty hero who suffered some loss of power is a perfectly acceptable character for level 1. Additionally level 1 in 5e is NOT a total noob. They are new to adventuring, but will likely be accomplished and capable warriors and wizards in their own right. Having a level in a class is a big deal in 5e. A 1st level fighter is already probably the best swordsman in his or her village. Someone a powerful lord would likely want to hire into their personal garrison.
Also, just in general to the thread; my last tabletop game started with a city on fire as it was being burned down by a full sized adult dragon and an army of kobolds and human cultists who were ransacking the place.
We were first level. This is an acceptable first level experience. And it is an official module for the game published by Wizards of the Coast.
Not all first level adventures start with killing rats in some guy's basement.
