Why doesn't Duolingo teach the verbs in the infinitive form. Ex: Nadar instead of throwing in nado into a sentence. Then it teaches you how to conjugate, using that verb. I found learning the verbs difficult, especially since I didn't know how to conjugate at the time. Just an idea.
I actually found it much simpler to pick up the conjugations without bothering about the infinitive form. In fact, whenever someone used to post the infinitive form, I had to look it up to understand what it meant. Whenever a new verb is introduced, along with the translations, we also get a link to the conjugation table. And, after a few verbs, one can see the patterns involved (for regular cases). This seems to be enough to complete the lessons here and pick up on conjugations. It took me sometime to realize the information in the table is enhanced to include newer details like past tenses, infinitive forms, etc. as one covers those skills.
Duolingo's strategy is very much "whole language," where you learn by listening, reading, and doing.
If you hover over a new verb--or an old one--you can see something like "conjugate it" at the end of the dropdown menu. Click on that, and you can see lots of information about how that word is conjugated. Using a dictionary like SpanishDict is great too, but the basic conjugation is available via the website version of Duo.
I also highly suggest keeping a notebook of new words if you're new to the language. You can make tables like these for your new words, or track conjugation, definition, and usage in a way that works best for you. I kept a notebook when I was learning Swedish, and it helped a LOT.
Also, as a sidenote, I recommend not starting the English-from-Spanish tree until you're much further in the Spanish-from-English tree. The íngles tree tends to assume a lot of knowledge that more beginner Spanish learners may not have. :/