Hmmm. The usual recommendation is your starter champ, which in your case might be Galek or Elhain... anyway, Elhain is better. 

However, Tayrel is even better than both and should also work as first 6*. Unlike Galek or Elhain, Tayrel is good enough that you can keep using him permanently, he won't become obsolete like they would at some point. He might be slightly more difficult / slower to farm campaign with, but he can definitely do it. Remember that his damage scales off defense so push his defense as high as you can, with high enough speed and accuracy. Crit rate and damage would also be good, but not at the expense of those other three things. 

Cillian and Coldheart should also be 6* but later. 

Tayrel  is  definitely  first.  As  long  as  you  have  good  enough  gear,  you  can  farm  12-3  brutal  with  a  5  star  champion.  I  did  that  for  a  while  before  6  starring  Kael

Thx  guys!!

how  much  def,  speed  and  acc  do  i  need  to  have?

this  is  how  i  have  Tayrel  now.

i

Those are ... really low stats. It's hard to tell from just looking at the summary, but a defense champ with only 1400 DEF is very low. You generally want upwards of 3-4K. Your champ is only level 50 though, so maybe once you get it to 60 you'll have better stats...

Thx  what  artifect  sets  is  best  to  farm  and  were?  

I wouldn't bother farming sets at the moment. Your focus should be on just leveling a full team of 60 for CB, so that you can start collecting rewards from brutal. That'll give you fuel to start getting more champs, since you'll often get void or sacred shards from the top brutal chest.

The sets aren't the issue, lifesteal is good, the main stats and substats are the issue. You should have a defence percentage main stat chestplate, which you clearly don't have at the moment. On gloves, it's more debatable but probably also def percentage for now, rather than crit rate or damage. 

Thank  you  for  tips.  i  will  go  focus  on  lvling :)

Good day Addy,

All great advice above. At the begining of the game - Lifesteal and Speed sets are best for campaigne farming/Clan Boss. Aim for 4-5(6 if you can) star gear and upgade the Gauntlets, Chest and boots first to 16(a ton of silver but your champ will be a beast afterwards) This is assuming you play to the champs strengths as mentioned above. Recomended for Tayrel: Gauntlets - DEF% / C. Rate Chest - DEF % Boots - Speed. Sub stats to lookout for: DEF %, C Rate, C DMG, Speed and ACC. Best of luck and keep grinding!