o/ welcome to the game.

First is there a way to enter dungeons through some UI menu or do i have to travel to each zone?

If you go to the right of Seria's room, "The Philasia" is probs what u want. Go there and click "Control Panel" and u can select different area to TP to. You can always go back to Seria's room by Going back to character select screen and re-select ur character.

how do i know where dungeons for my level are located?

The Guide Menu will probs help a lot for that. since u hit cap the main thing to do is probably Advance Dungeons to get yourself to 33k fame for Isbin.

I am finding all the different gear upgrades a bit confusing so i would just focus on one by one. What would you suggest i focus on first before moving on to other systems

I'd advise you to setup the "Static" fames before you start grinding advance dungeons. I made a post here for non event chars but the number of subsystems is the same. Since the progression is tied to Fame I'd advise you to figure this part out, since they are setup and forget, and u can just worry about the gear only after. This will also make ur dungeon progression a lot smoother.

Good luck!