Anyway apart from the above , re memory cards. I only use sandisk and only had one fall apart in over 11 years.
So first things first. the spec on your camera should give the max MB/s speed it can accept. Mine allows up to a max of 200 mb's. Cards usually 170 mb's should be fast enough to prevent buffering
next is memory card size and I use normally 128 GB card.
however being or trying to be clever I did use 256 GB card size on the norway- fareo iosle -iceland hols.. Even though that was above the recommended 128 GB size what happen was it split the 256GB cards auromatically intoi 2x128GB sizes
class 10 is the norm
There are four different speed classes — 10, 6, 4, and 2. 10 is the fastest, while 2 is the slowest.
there is also a number 3 in an U which is tghe normal video speed and nothing to worry about
I also only use SDXC your information book should ay which you can use.
I can pass on a couple of tips which might help
Panning a scene to fast will cause juddering (shutter roll). So to get over this if you start with a subject on one side of the screen pan slowly enough so it taks 7 to 9 seconds to get to the opposite side. This will slow your panning down and make a video a lot better. One danger is accidently caputuring a child in the video. I tend to rather wait until the area is clear and been thanked by several parents for doing so.
Don't try walking with it I find it nearly impossible to keep the camcorder steady and you also pick up breathing and footstep sounds. I norfmally recode In MP4 for nornal vieo/ MOV format may need an editing suite that can handle it such as Wondershare 13 for example.
sound
is anothe issue and which extrnl mike to use as the camcorder one is useless , Oh by the way that flap on to revealing the hot/cold shoe I held back with bluetack as it kept baning against the camcorder body and could be heard in the recording
I have tried several different microphone from directional to surround and eventually found the ideal one that does both. Most use Rode but
please take my advise this time . this is the reason why Rhode have fixed audio cable and if damaged you mike is kaput. also uses 9V square batteries not the best idea g etting repalcements or for recharging.
I also had the sony microphone which was directional if my memory serves me correctly and not that good on sound quality.
AS i sai I have tried several and the all time best is one you wuould not have heard of. that is the AZDEN SMX-30V, not tghe cheapest but far from tghe most expensive and the sound quality is first class
So why this one? well apart from going from stereo to directional via a dial id has a detachable audio cable so one can use vittually any reasonable lenth away from the camcorder. It power up via AA batteries or off camcorder battery and tuns off when the cmacorder is turned off. also had the high /low pass fikters etc as shown below

then there is wind noise to deal with so a good muffler is a must. Hear again I have tried out several -spong and hair tpes ' the best I have come across is made by Guttmann in germany
The world`s largest manufacturer for microphone windscreens, windshields for intern, extern microphones, Voice Recorder. Deadcat for Smartphones.
www.mikrofon-windschutz-gutmann.de
smaller microphones have a "tinny" sound
this hasn't and good distance range as below as an example
View: https://www.youtube.com/watch?v=v-63EXbCOw4
Sony AX53 with top flap blutack to the mic to stop banging
