First of all : be vigilant! don´t assume you can run through this game like nothing else.
Watch your surroundings , look where and how many enemies are ahead of you .
Plan your attack , dont just run in ! You will most likely be overpowered and killed .
Look for helping stuff , like mushrooms , loot crates and the alike . Knowing where to go when you are in a pinch will help you a lot .
Also , always keep an eye on your endurance bar . no endurance = you are most likely done .

COMBAT
Managing your endurance is key to get better in this game.Never drain your stamina completely so your are able to do something if things won´t go the way you have planned. Also , keep in mind that you still could go into hardened mode to get your stamina back.

PARRYING After finding the "tarnished seal" you get the ability to parry. ( F or LB on xbox controller) gives you a huge andvantage over your enemy plus a succsesful riposte (RB) heals you . this form of healing will come in handy the whole game through.
Learn to parry the standard enemies first: as soon as combat starts, take 2 steps back and wait for the attack as soon as you would get hit by the attack , use the parry button . It might be hard at first and might take a while to get it right , but being able to parry is satisfying ;) Worth mentioning is your parry item will give you a "hint" which attacks are parryable and which are not. It will flash red if enemies use those attacks . Just dodge or use harden is this case .Most enemies will take some time to recover from said attacks , that is your window to strike them down !!

Running into ememy groups will most likely kill you , instead try to lure them over to you 1 by 1.
If you mess up and the whole bunch comes running , try to keep them in front of you to not get surrounded..Or , and this might hurt your pride a bit , run away to face them once again in the way suiting you
BOSSES
in any souls like , there are very hard to kill mf´ers who most likely will feel like unkillable.Here are some hints for those:
Don´t just run in and fight , watch the boss first . what is he doing , what is his moveset. where does he pause between attacks? Finding those "sweet spots " where you are able to hit him without taking damage is key in this game and all the others alike .
THE GAME WORLD
like many soulslike , this game is packed with stuff to discover, search every where for goodies.The mushrooms have a special place in the game because they grow back after a short time.This makes it easy to farm a lot of them over time. one is right next to the main base of yours (facing down the road, look to the left , can´t miss it)
Last bit of advice : Don´t take it too hard if you die . Tenacity is key in this game. Die - try again , get better , SUCCEED: if you feel tired or dying again and again , take a break.

And this concludes my little guide , i am hoping it will be helpful to enjoy the game as much as possible. If someone wants to have more help in this game or the other soulslikes ( dark souls 1 - 3, sekiro, star wars : fallen order for example ) feel free to contact me .

very useful site for new players :

https://mortalshell.wiki.fextralife.com/Mortal+Shell+Wiki

GIT GUD