I tried to do some digging on my own through Google but I'm not much familiar with networking terms and alas, I learned pretty much nothing. Could anyone here explain the differences between these two and which should I choose? Thanks in advance!
Personally, I use DNS-over-HTTPS (DoH) since it's less likely ISPs will block it, like they could (and likely will as time passes) DNS-over-TLS (DoT) which uses its own port 853 and DoH uses the standard HTTPS port 443. I've heard claims that DoT is a little more 'secure' than DoH (due to network admins being able to monitor DoT DNS queries and block them if need be whereas DoH queries are encrypted and sent with normal HTTPS traffic), but even if that's true what good will that do if your ISP decides to actively block DoT. So I'm sticking with DoH until I hear/see otherwise.
Also worth noting that both Chrome and Firefox now have support for built-in support for DNS-over-HTTPS as well.