There are multiple ways to trivialize the difficulty, from simply learning the maps to reading some guides.
However, if you're impatient or new to shooters - devs let you replay the tutorial quest unlimited times!

To do so, exit to main menu and click training mission.

You will be using the same gear you have on your character in main game, so nothing prevents you from bringing an LMG and huge backpack for loot. Starter guns will work though if you're an OK shot. I used an AK with 60 round mag since 5.45 is free both from scav vendor and from the euruskan.

Of course, you get to loot the starter crate there which has a random mix of 5.45 rounds, 12ga, and base medkits. You'll probably throw all of this away in the end to take more valuable loot, so only take what you will use (probably the ammo type you prefer). Then you can turn in the water barrel and sprint to extract area. Cyborgs will chase you, 5 of them spawn per wave but only 1 has legs. They take about 5 shots of 5.45/2 headshots, 12ga drops them in 2-1 shots. You can simply crouch somewhere near the extract and farm the cyborgs for unlimited XP. I usually let them come close so they're easier to loot. Generally once you shoot 2 waves, next wave will take long enough to spawn where they will miss the fight and wander aimlessly. At this point you can loot (I generally Take All, too much hassle searching and loot values per kilo aren't that different). Depending on size of your rig (rig vendor lets you buy bigger rigs and upgrade the bins in rigs you have!), you'll be able to carry loot from 10-40 cyborgs once you dump your ammo during final looting. Each cyborg is roughly... 3000 worth of loot I feel? Once you extract, you'll get XP for kills and I think looting, extra 1000 XP and 10k cash, and crucially +1 water for repeat completing tutorial quest (plus scav trader rep). If simply finishing quest (kill only 5 cyborgs) and running out, its possible to get +1 water per 2 minute raid, getting 80 days worth saved up within one play session.

Killing cyborgs slightly upsets the euruskan vendor but selling him the loot from them gets you like 3x more rep than you lose. You can sell cyborg parts to someone else - I think those upset him too.

PS. The rest of the gaem can similarly be trivialized with knowledge. For example, knowing which items / actions upset Hunter Killers lets you avoid them quite reliably. Enjoy the beautiful battlefield spectating!