How to know what card to draw while doing a reading I only doing it for myself to develop my intuition
I have heard that the card would be hotter than the rest but that’s probably only if a spirit is involved
I still only use just poker cards for it but I’m planning to buy a tarot deck
Short answer - you just “know”. Longer answer but still it’s very individual - the more you work with cards the better you feel their energy. Can’t really describe it since as I was told by an old witch (the kind of witch that were living outside the villages, curing cows but also prophecing and doing dark stuff simple folk couldn’t even imagine, they’re so rare these days…), I have natural gift to sense which card - or rune, or anything really - wants to tell me something. It’s like a slight vibration on my skin when I look at the card, truth be told I can easily enter very light trance and disconnect any external influences from myself, so the card nearly screams “me, me!” 
I work with Tarot by the way, my very personal deck attuned to my energy. Never had experience with particular card being hot, it’s just a vibration in my case.
It takes practice and switching off everything you ever read about how to do it, honestly. Even what I wrote, read it, forget it and try to listen to the cards, as blunt as it sounds.