Should I open the chakras first or...?

Hello ! I recently started my spiritual journey after reading The Untethered Soul (Michael Singer) and quickly started, when meditating and in my day-to-day activities when i'm aware of my consciousness, to feel a warm, nice energy in my upper body. When meditating, when i focus on the Self, this energy can be overwhelming because at one point it goes to the head and sometimes around my ajna chakra. I feel like i'll get out my body and usually get a little afraid so i ask it to calm down.

For now, i'm not very informed about spirituality but I know one must be cautious when it comes to the "third eye" so I was wondering: should I first just focus only on the Self and let the energy come more and more, or open my first chakras one by one by putting my awareness on them before?

Thank you!

Edit: little questions less important: 1. When a chakra is activated, do you feel it every single time (like that i'd know if it's activated); 2. Even if i need to activate my chakras first, do you think it's safe to let the energy come as i do now in my day-to-day activities? Since i'm can't be as aware as i am in my meditation for now, this energy isn't overwhelming but it's very nice to feel so i was wondering if i could let it be:)