Please don't practice new ADC's in PvP games, do a few bot games first.
its unfair to your support for them to have to support someone who doesn't know what they are doing. The same is true for supports, its unfair to your ADC if you go in as Alistair and accidentally cockblock your ADC from getting fed.
I also realize that doing a few bot games won't change a pvp game from being basically another practice game, this is fine, it's inevitable. It's just, without those bot games, you won't even know the basics of your own champs timing which will be really depressing for your support, not to mention your team, but its really the support/adc that suffers in this scenario.
Imagine if you are in mid or top lane, and there's another guy there taking the CS but all he does is feed the enemy. can you imagine how that would feel? your agency is robbed. everyone has to learn ,you say to yourself, but...this guy is 30 CS behind for no good reason. you can't even take his CS either because he needs something to mb possibly pull ahead.