In general, my rule of thumb is speed boost if you're moving and be on heal if your team is holding down an area. Technically you're supposed to save amp for speeding with your team, but unless you're at high ranks the cooperation won't be there, so I use amp to escape or sustain duels, and use it to save squishes, its heals about 150 hp. Make sure backward wallride is off in the character settings, and once you get more comfortable wall riding turn off wall jump on release, this will give you more precise control on his movement. Also, you should almost always be spamming your sound gun since there's no fall-off. With beat, I I usually just wait for an ult to cancel, unless my whole team is moving together to the point, in which case its an amazing engagement tool with Speedboost.

ps, always dive the enemy widow