PS4 here.
Here are some suggestions:
0) Play on Famfrit because you know you want to play with me (this is a joke)
1) Get a keyboard if you can-seems like you already did.
2) Make macros that will correspond with various situations. Example of macros I have:
a) Macro that tells party I'm new.
b) Macro that thanks the party after a dungeon.
c) Macro that tells the party that I am being attacked by an enemy and also which enemy
d) Macro that marks an enemy, puts it on my focus, and sleeps the enemy while telling the party what I'm doing.
e) Anything else I might need to say quickly.
3) For specific advice, go to the specific DPS/Healer/Tank forums.
4) As a tank, mark the targets you want attacked. As a DPS, attack the target that the tank is attacking (unless you are finishing off a target-most tanks will switch when the target is at low health). As a healer, watch your aggro bars (there are three main ways to tell aggro) - don't heal the tank until he has aggro.
5) Aggro bars: When selecting an enemy as your target, the party list will have these white bars that slowly fill up with white stuff. This is your enmity listing for that mob. The more full, the more aggro. No white bar=no aggro at all. There is also a monster list with green->yellow->orange->red. Green means low enmity on that monster. Red=you have aggro. Orange = you are about to take aggro. (There are more minor details as well, but not trying to hold an aggro class here and that stuff is way too advanced for a new player to try to learn). Third way to tell is the targetting lines. When you switch targets, other players will see a blue line going from you to the target. This works for allied NPCs also. When enemies switch targets, a RED line will go from the enemy to the target. Watch these lines, especially as a tank or a healer.
6) Listen to advice. You might not use the advice, but if someone is telling you something you didn't know, listen. Sometimes the advice can give you some information that will help.
7) Early game, conserve gil. This could mean using favored locations or even free locations where it will save you the most gil. (example: I could warp from one location to another for 400 gil, OR I could warp to my favored location first then to the location for 300 gil total. Or I could warp to my free location and then to the location for 250 gil. Another example: From ul' to horizon is 5 gil. From ul' to vesper bay is 30. From horizon to vesper is 15. So for a LITTLE more work, I save 10 gil. Another example: I can pay 260 to teleport to from one location to another. OR I can take 5 seconds of my time to change areas and pay 100 instead.
8) Get cross class skills that will help your main class with your playstyle.
9) DESPITE the many good things about your jobs (class upgrades), there are advantages to using the base job. Example: As a conjurer 30, I can use skills that turn me essentially invincible for a few seconds which could be more important than stronger heals. As a WHM 30, I only have access to some Arc and THM skills and have stronger heals. Which is great except I'd rather LIVE and have to do a little more work healing than die because I wanted easier healing. Look at the advantages and disadvantages and choose accordingly.
10) Especially if you are new, for each class you do, do every guildheist and dungeon. And if possible, trials.
11) If you play with someone and you really like them, ask what their server is. If they happen to be in yours, you might want to join their FC! Don't join spammer FCs, those tend to have some benefits, but generally it is all about numbers. They are just a "beneficial effect" FC for the most part. Join a FC where people want to help you, give advice, give items you need, etc. That can go a lot further than a "beneficial effect" FC.
12) Early game, do a lot of Fates to hit 15 (only for combat classes). Then you can start doing dungeons or hit 20 with one character so you can unlock mounts and grand companies. (You can change grand companies though there is a cost for doing so-Ul'lad has the easiest company to start with). You can only change companies once per month and it costs 50k gil to do so. I actually would almost recommend doing your preferred company last rather than first!)
13) Because 13 is one of my favorite numbers... Do your daily roulettes. Either with a lower level character for the exp or with a higher level character for the tomes and other rewards such as gil or seals. You unlock tomes by hitting 50 and finishing the main storyline. I highly recommend rushing with one class to finish the story so that you unlock tomes since one of the tomes has a weekly limit and all your combat classes get exp bonuses if they are lower level than your highest level class. (Hint: Tank is easiest to level due to the fact that tanks are rare, healers are the next easier (this is purely leveling, the actual playing of them is hard))