So having about 23 hours logged into this game already and seeing quite a bit of questions and such in here I'm gonna try and answer a bunch and some tips to help people not quite understanding certain parts of the game. Hopefully this helps someone.
Well start with
movement. As many have said. you can't stop moving or start walking around. KEEP MOVING. If things are too fast remember that holding LT aims and slows things down a bit. Also if they're still too fast for you, look around, is there a highwire that goes in a circle or square? If so just grind that around in that circle and you'll feel like you have more control. Also if there isn't just get on a ledge or wire that has some length, and grind left for awhile, hit right+X and switch directions for awhile and repeat going back and forth. obviously blowers, herkers and such, will target you a little better, and if so just grind or jump to a new location. Remember things like if you're undergrinding, you can press X+A to do a super jump up. Also if it looks like you're gonna land on the ground, ground smash by pressing B and then press A again quickly and you'll do a super jump off the ground and not lose your combo. And honestly, just play the main story until you unlock air dash, and then just practice your movement, the traversal challenges and point challenges are great ways to help you learn while in a set area that you can repeat and also learn currency for completing. Also don't forget about wall running, it can be especially helpful when it looks like you can't quite jump up onto a roof just wall run and then jump again to reach those spots.
short movement video and combos.
Currency - You'll notice you get both cash and Overcharge cans as currency. Cash is for clothing and other cosmetics purchase and the cans are for buying weapons, ammo, and collectible maps.
Now
collectibles, there's toilet paper, cameras, shoes, neon signs, Fizzy balloons. All of which besides being collectible achievements also are used as a currency to buy amps from floyd. Some of which are cosmetic, but most add a new aspect that might be awesome to you depending how you play. There are maps you can buy to find these in each section of the city, but are quite expensive and so I wouldn't do it until later in the game, focus more on buying or saving for guns you want. Also worth noting there are billboards to tag(they're white and say 'your advertisement here') smartphones, eavesdropping, and highpoint(looking through the tourist sightseeing machines) to collect, they aren't a currency like the others but do give you something for completing them. Also I'm pretty sure after you find one of these you'll be able to buy the map to locate them easier.
Amps and Weapons - Amps are basically ways to augment you and your weapons. You can have 5 amps on yourself, 1 melee, 2 personal, 1 epic, and 1 dive bombs. It's all pretty self-explanatory, but just know the melee effect doesn't happen until your bar is at lvl 2, and the epic one doesn't happen until lvl 3. Weapon amps add a special effect to a weapon, and can't be used until the weapon is lvl 2. You'll lvl up your weapons by simply using them and each upgrades usually adds more ammo capacity, damage, and for some blast radius. Just experiment with different amps combos. One of my favorites that I haven't seen mentioned much is putting an amp that has a change of freezing enemies on hit on my acid sprinklers. They're always hitting so you can usually freeze things like herkers without having the freeze bomb gun on. ALSO look for combo of weapons that work good and certain enemies, like starting herkers on fire and then pistoling them, or freeze bombing, then acid rain, the tnt teddy, possibilities are endless just use your imagination.
Overcharges - You'll unlock this section at some point while going through the main story, might not notice until you start earning badges. Basically these badges are a currency to unlock overcharges that you want.
These are permanent perks of which you can only have 6 on at a time. It's pretty simple to get badges, if you grind a lot you get grind badges, if you use single fire guns alot you get single fire gun badges. You can upgrade each overcharge 4 times. So something that only give you 5% more damage doesn't seem like a lot, but it can get up to 25% by the end of it. Just unlock and use them based on how you play/want to play. Dying a lot? works towards upgrading the health badge, or reduced damage from a specific enemy type.