So I picked up with Gwent pretty late into the game. So I lost track of where I was supposed to build my deck as a novice, almost every merchant I find beats me, unless I get really lucky.
Any advice?

bump

Any advice, go buy as much cards as you can find. I'm in the same position lol.

I won everything with the basic deck for now.
AI is dumb as fuck even if he has good cards.

So. I played against everyone I could.
and I bought every cards.

The fact is, you need to find ppl who play to beat them and get a new cards. And for example you REALLY NEED to fight ppl like Baron,Shaman etc. They will give you an awesome card each time. It 's a quest so you will find it easy :)

True, as a long time Yu-Gi-Oh/MtG player I can definitely agree the AI is totally awful lol.

Question for you though, can you win more than one card from each player? I've played some people 2 or 3 times and they resort to giving me actual garbage like leather scraps.

Lots of good advice in this thread:

http://www.gog.com/forum/the_witcher_3_wild_hunt/am_i_the_only_one_who_doesnt_get_gwert/page1

As a person who spent a lot of time in Gwent and has all faction decks I would suggest you to do the following:
You can buy cards in taverns mostly hover look for them at every merchant(most of them are not that good but not bad to begin with) then i would suggest you to play with every merchant alchemist etc, cos they are not that strong as the special card holders.

Begin to play with Foltest who is able to make good weather as your first deck will be Northern Realms and always keep minimum 22 actually ammount of cards in your deck(you have to leave only the best cards and dont put rubbish into it) that is how you will be able to get your best cards with higher chance in those 10 that you get in the beginning of the game.

Don't hesitate to use training doll cards because it's pretty handy(especially to get enemy spy in your hand if you havn't got your own) but don't put way too much weather cards in your deck basically 1or2 will be enough and in case that you have special ability of Foltest you don't need "Good weather card"
If you want more advice you can send me private message. Atm i play for Nilfgaard and have 6 heroes in my deck and i don't have any card in my lower then 5 points.
P.S you don't need to play more then once to get cards.
P.P.S If you have only stock Foltest card you should not put into your deck mist cos your leader ability will cast it.

I havent played gwent yet, besides the first time. I'm like level 10 now and want to try it a bit to have a second source of income. But I still have my basic deck and don't want to buy new cards atm because I need my money for other things.

Do merchant decks get alot stronger during the game or should I go back to the start to pick up gwent? And if you fight people like the baron for cards, do you loose your chance of getting the reward when you loose? Or can you keep trying until you win?

No, you can only win 1 card per player.

You can keep trying to be honest i am even not sure if you will loose your money or not. Besides Gwent is not good source of income the best source of it are your contracts.To begin with start from playing with some merchants but then you have to beat some guys like baron or kid from the village(was my first special card actually)

So I just found out I could buy new cards, that made everything easier.

Most usefull cards are heroes of course and those that let you revive other cards.Oh and heroes cards of course i have 7 heroes in my desk so i am literally rollstomping everyone.