This game may seem very simple at first glance; just auto-route and let your character kill stuff. But it's considered grindy and therefore not recommended to main on a phone. In fact I've heard of people's iPhone bloating up for playing too long... You can use your smartphone to play on the train or something to clear main quest, but certain things require grinding. 
Some tips: 
1. Adena (gold) might seem to come easily at first. Later on you need a ton of it so don't be fooled 

. Turn off auto-pot to save gold. Save soulshots for difficult dungeons. 
2. Gear have different grades; C, B, A, S, R, SR, UR. To get higher grade, you need to fuse two level 30 gear of the same grade, or fuse one level 30 gear with armor/weapon/accessory ingots, which I wouldn't recommend for non-Rares below R-grade. More on rares later. 
In general, story quest easily gives you up to B grade. To get A grade, you need to fuse B grades or get them from calendar login (unsure if global have this function lol). 
To get UR, you need 500 of armor/weapon crafting item with a UR blueprint. Takes forever lol. 
2. There's two kind of equipment: normal and rare. Rares have a blueish/purplish aura in their thumbnail icon, and can be gotten BY CHANCE through fusing two A grades, or above. Therefore, fusing As for a chance of getting rare S grade is the cheapest way to gamble for rare. 
For rares, I do not know if it is worth to chiong normal gear since it's cheaper or gamble for rares. Later on, you can up your gear level to 30+ (I think till 36). To do that, you need another rare level 30, so you can see how expensive this is going. I have heard of people going for normal gear only all the way to SR and level 30+, but so far the others who are playing are working on rares. 
Welp, you can choose to use SR normal until you get rares. Or maybe in the end, the rares are for people who swipe credit card. Personally I'm just gonna work on normal gear, and only settle rare gear if I get it coincidentally. 
3. (TBC) Certain rare gear have stats that are better for PvP or PvE. 
4. There is recommended power rating for each level. Your character also have ratings like gear (C, B, A, S, R, SR rating). Power rating comes from many factors like your skill level, your character level, your gear, etc. In general, if you feel that you are popping too much pots just to clear simple kill quests, it means that you need to pause leveling and work on your gear or work on your Monster Atlas. Usually this happens when your character rating is B or C grade. 
5. Monster Atlas is basically the main grind of this game. You need to kill monsters to get Monster Cores. After gathering a certain amount of Monster Cores, that monster entry in the Atlas will go up in level, giving you some stats that can also boost your power rating. If you plan to go afk for long hours, you can consider grinding out your Monster Atlas. Personally, I prefer to farm the grind dungeon Atlas entries first, so that I don't need to run back all the way to beginner maps. 
6. Continuing from above, chionging level is not everything in this game. Chiong too fast and the game whacks you in the face. Recommended is to really slow down after level 80, but tbh, at around level 30 you will find that you can't just eat all the boss attacks anymore.
7. At beginning levels, you will get a shitton of C-grade gear and feedstock. Feed them into gear of up to A grade only, nothing higher than that or your gold will disappear like your monthly pay :< 
8. Continuing from 7: You can opt to not loot anything below C-grade. This is especially useful once you got all gear to S-grade or simply having nothing lower than S-grade to fuse. Don't worry about having to hoard C-grade stuff. You get them very very easily. At higher levels, B-grade drops easily as well.
9. Main quest is pretty important. It unlocks game features and new map areas. However, these are level capped, and sometimes you will find that you cannot continue with MSQ since your level is too low. That's why dailies are important.
10. Dailies are in the form of dungeons or monster kill quests. Dungeons should be done first, shouldn't take too long (except for grind dungeon). Monster kill quests are the least time-efficient since you need to kill large amounts of mobs and should be left at the back of daily routine. However, these quest give quite a lot of EXP. Some people don't even do those quests since they feel that they are weak for their level.