The first thing I would do if I were you would be to look for and join a guild that you can enjoy. An important part for me was finding a guild that used discord or some sort of voice chat, but either way, a guild will make this game a lot more enjoyable. For now don't worry about getting a horse. Run everywhere so you can level up your breath. Once your breath is lvl 30, then you can start using a horse.
Since you are level 50 here's what i'd start with. Open the quest log and switch over to the "main" quest tab. Complete all of those quests until that log is empty and then move to the "suggested" tab. Here you will find a quest chain that rewards the abyssal weapon which gives 84 AP. Do that quest chain I think the first quest is called past glory. Once you have this weapon you can start grinding for the asula accessories, all 6 give a total of 45 AP. If you already have a weapon that gives you around 84 AP, just focus on upgrading a yuria weapon. Next, get the accuracy offhand for your class (Vangertz, Saiyer, Bronze, Helrick) at least to +7, this will get you 2 AP some DP and a bunch of accuracy/evasion. This gives you 131AP.
As for armor, the best you can do right now is grunil or heve, but they are also the most expensive. If you are unfamiliar with enhancing I'd recommend you use agerian because it will be easier to repair the max durability. The difference between grunil/heve and agerian is minimal, all you are really aiming for right now with gear is to get +5 attack/casting speed and +5 movement and crit if you can. Get your armor to at least +10, this is pretty easy to do without failstacks.
With this your AP will be 131 and your DP will be 129.
Once you've reached that point, you can begin to upgrade you gear. don't worry about accessories right now, the asula set is pretty good. You'll want to start working on a weapon, ideally for PvP a Yuria. Prioritize upgrading your weapon first, aim to get it to DUO. Once you've done that get all of your armor and your off-hand to DUO.
With this your AP will be 143 and your DP will be 231.
For now your DP is going to be way higher than your AP and I wouldn't recommend getting the AP off-hand until later on when you have more accuracy to support losing the accuracy off-hand. Even if you had the AP off-hand right now you'd only be at 158 AP. I wouldn't recommend PvP'ing until you get at least everything to DUO.
Ideally, you'll want to grind until you are 56, this can take some time but it shouldn't be much. Once you are 56 go back and do all the general and reoccurring quests that you see, this will level you to 59 very fast. Once you're 59 the real grind begins.