if you just want to do the basics then go to an un-populated campaign you'll get less grief from "tourist hunters"

Check out this thread, video, and images. It offers some great info, especially for new players. it may help you decide... https://forums.elderscrollsonline.com/en/discussion/508634/pvp-class-summaries-the-good-the-bad-and-the-ugly

Impen trait on all armour. Go for at least 5 heavy armour to start with and around 28K-30K health, this will give you a little time to react and self heal. Have enough soul gem with you so you can resurect allies.
Magica Templar is a good starter class, have powerfull self heal, extended ritual/ritual of retribution removes negative effect from you.
Most important: Dont give up:) You will die in PVP, but that is a part of PVP-ing.

Hope you will enjoy PVP-ing.

My advice is bit different, but i think it may make your game experience less frustrating (and more rewarding) at beginning..

if one of your toons is healer, i would start with them. Even if you suck at PVP, you won't gonna feel totally useless, because you gonna contribute to your team. This doesnt mean that you shouldnt PVP - but it will give you a way to do some meaningful stuff beside laying dead on ground.

Also buy (at least) few ballistas (normal ones, not any fire etc types) so you will contribute even more (tbh this is must in cyro, don't be bystander while others are sieging). If you earn some AP, you can buy meatbag catapults which are very fun to use on big enemy groups and help a lot if used correctly.

1) wear inpen. Wear MORE impen
2) prepare to die a lot and don't take it personally
3) play the character you best understand and have the most experience with

A few minor tips;
1) If you see a dead friendly in the middle of nowhere, give the carcass a wide berth; It's a trap!

2) If you sense danger, ready your defenses. Especially if you're exiting a contested keep/castle or collecting a sky shard. Shield first if you can. Apply a hot as well.

3) Don't get tunnel vision. Skilled players will exploit this and lead you to your death.

4) Have fun. That's the entire point, yeah?

The most important thing is your mindset. You gonna die. A lot. Even the best grand overlords die, so take dying as part of the pvp and don't get upset about it. Just res and get back to the fighting.

Prepare for survivability and sustain: tankiness with high defense (heavy armor, impen trait, 25k+ def, 25-30k health in Cyrodiil with the pvp bonus and food), high resource regen (~2k regen on your main resource), and with some form of self healing. You don't want to be a glass cannon who die or run out resources in 2 seconds at the very beginning of the fight, you want to be up and kicking for a longer time

Feed your horse (and do it in advance), you need horse speed in Cyrodiil otherwise you not get there to the action in time. Also use rapid, you can easily have it on your backbar all the time. Do the introduction quest, which teaches you about sieges and gives some AP to immediately level up the assault skill line for rapid.

You're below 50 so pay attention your gear level, you want it max 5-6 level from your character level, generally you want to switch your gear at X0 and X6 levels (16, 20, 26, 30, ...) Crafted gear works well in under 50 campaign. For magicka I would recommend 5pc shackle + 5pc seducer + 2pc torug, for stamina 5pc hundings or ancient dragonguard + 5pc eternal hunt + 2pc mechanical acuity.

Below 50 you only have the first few skill from the class and weapon lines, so you mostly have to relay on those, and also from magick and psijic lines if your'e magicka, or from fighters guild if you're stamina. You also want vigor as fast as possible if you're stamina.

As of weapons, if you're magicka I'd recomend destro front with resto backbar, if you're stamina I'd recommend stating with 2h front and bow backbar. As stamina you can try s&b backbar too, but at the start I would recommend more of a mixed ranged melee approach instead of a full melee.

Any idea when midyear Mahem will be our?

When you get into Cyro just type LFG in zone chat, you should get into a group fairly quickly running in a group will make your life in Cyro much much much easier.

Your epic PvE gear wont do you squat in PvP, Id get some gear.

When you're in the group follow the crown at all times

Understand that you will die, and can die fairly quickly but thats part of the learning curve.

Lastly have fun thats the most important, I spend my entire time in Cyrodiil and always have a blast