Since I missed a lot of cards, do I have to grind a lot later?
I guess you have to start the other city from level 1 to get the high level chains, right?
No, you don’t have to start at level 1.
You can start at any map you want, the main quest automatically unlocks once you enter the map unless they don’t have main quests on it.
There are exceptions though, but most of them are like that.
Not such a big deal,just go and do em now 
You missed not only worthless lvl 1-2 exp cards but stat points. So just do them whenever you feel like it (statue’s stat points + main story quests) And do starter area too - Zemyna’s statue tutrorial quest for 1 stat point
You can skip the ones you feel will give less benefit to you. e.g. the maps that give lvl 1/2 cards.
Maybe just do the main quest of orsha, and skip the side quests that give level 1/2 cards. Orsha opening gave a lot more leeway, and you can make up for that small amount of cards that you’re going to leave behind.
Also there’s dungeons, so you’re still bound to get exp, just save up for that lvl 165 exp wall though(if its still there)
You can do that quest on starting on point and do the main quest (Yellow ones). Its faster and only few.
The wall is still there, you have to grind from 150ish-160 at demon prison or dina bee farm.
There’s also cards, heard you still need a couple hundred or so.
but at that point the small amount of level 1/2 cards wouldn’t matter.
So yeah i think skipping those quests would just save OP time lol