There’s several (and free) options available, but the platform that made me actually start learning vocabulary was Kitsun. It offers all the mainstream decks (including Core 10k - probably the best version around) and they actually look good visually (not bland looks like most decks on other platforms). It also has a dictionary integrated, so you can literally search for a term and make a flashcard for it right away. It’s very friendly-user 
It’s however a paid platform, but offers 14 days of free trial
If you really can’t afford a paid platform, you can always study the deck on Anki. I recommend this version of the deck
I usually try to do reviews during the day (most of it in the morning) and save the time for reading to around dinner time I think it’s best to have different schedules for both because it allows to have a better focus. You won’t be worrying about doing reviews during your reading time because you do them at different times of the day 