Materials
Here is an application for learning Finnish: https://www.duolingo.com/course/fi/en/Learn-Finnish
Using resourse LyricsTraining you can learn Finnish through music and the lyrics of your favorite songs. It's also available as a smartphone application.
For self-learning you can also use this resource: http://suomenkielisanootervetuloa.fi/
Here is one more resource for self-learning: https://uusikielemme.fi/
You can also use Wiktionary, there you can find a word in different forms and see the inflections of the word. https://en.wiktionary.org/wiki/
If you want to speak Finnish fluently someday, I recommend you to switch to Finnish-Finnish dictionary as soon as possible, here is one you can use online: https://www.kielitoimistonsanakirja.fi/