I finished upgrading all my armor and weapons to PEN TUVALA. I want to work towards end game gear. Where should I go from here?

Probably best to search the net for various BDO gear guides.  There are different approaches and those have changed over time.

Nowadays the next stop - after graduating season - is to go to Jetina and start on boss gear exchanges there.  There's pros and cons to that approach, and you don't necessarily want to do all the pieces through that since it's cheaper to buy the last few off the market. Also, some people skip the boss weapons and start looking at Blackstar earlier.  Keep in mind that finishing the Abyss One - Magnus quests gives one boss armor piece - your choice - as a reward.

Then there's accessories.  Season rewards can give you three PEN Capotia pieces (belt, necklace, ring), and you can get a PEN Crescent ring through Jetina (for some work and cost).

All of that gets you on the road to soft cap, wherever that is now.  Grind for silver, accumulate Caphras stones, try your hand at enhancing...

Hard cap - "end game" - is something like 750GS, depending on build focus, and other stats become important.  Put that on long term goals list.

Meanwhile, also take a look at artifacts and lightstone usage, and crystals.  Those can help a lot in various areas, depending on what you are doing.  There are more guides for those out there on the net.  And then there are things like boss hearts for more stats.  Do world bosses for a chance at those, and if you have silver and (a lot of) patience can order from the market.

This coming from someone who is still on that path.  Those who have arrived already will have different perspectives.

Edit: Took a closer look at your GS, noticed that your Tuvala accessories aren't all PEN.  You might want to do those too, they will hold you over until you can pick up the Capotias and Crescent.  That will give you another ~25 AP or so.  Oh - and do your journals for another few AP/DP.  And there are a few more quests for an AP/DP here and there.

look her

https://garmoth.com/guides/post/jetinas-guaranteed-pen-boss-gear

and

https://garmoth.com/guides/post/jetinas-guaranteed-pen-accessory

and

https://www.blackdesertfoundry.com/abyss-one-magnus-walkthrough-guide/

and

https://www.blackdesertfoundry.com/category/all-guides/page/7/

(all journals)

The road is long and winding my friend. 

Others have pointed out guides on gear.  You can get your first piece of IV boss gear that can be upgraded by graduating the character and converting 1 of you armor or weapon slot items.