I’m still fairly new as a player compared to most people here, and I can tell you, there’s a treasure trove of information on how to play the game on here if you take time to go through old posts. I would suggest looking through the forum for some of the posts on things like how to do well at PvP, what ferocity is and how to figure it out, that kind of thing. Use the search feature too to see what comes up for a topic you are interested in. The Fandom wiki for the game is my other favorite source of information, especially on dinosaur stats.
On the Tapjoy rewards, I did a number of these when I was still new, mostly one for downloading games and some charity donations (which I do anyway so seemed a good way to use my monthly charity giving to benefit in the game). Watch out for ones that want you to fill out surveys… those appeared to me to be typical of telemarketing scams to collect phone numbers and emails. Also, they pretty regularly have promotions where the amount of the reward is doubled, so wait until then to do them. By the time I used up any that I was interested in doing, I was far enough in the game to generate bucks easily enough on my own via PvPs, tournaments, and other game playing.
But I did have a lot of issues too with rewards not showing up, but thankfully Tapjoy is VERY good at following up on support requests. When viewing the list of rewards you can get, click on the menu button at the top left — should look like 3 lines. That’s where you can access the list of rewards you’ve selected, which ones were rewarded, and which ones are still pending. After some amount of time (48 hours I think but might be longer for some), if you still didn’t get the reward, you can send Tapjoy a support request. This will usually require a screenshot to prove you completed the request, such as something that shows the level in the game, or a receipt if you had to purchase something.