With cryptocurrencies you can never be 100% sure.My favorite altcoin is DeepOnion, because with this community and active developers team, while the coin is still cheap,I think it could really take off.
Personally I read a telegram channel Satoshi Advice. It’s an aggregator of many other channels with crypto trading signals (more long-term than short one). It’s convenient as you don’t have to monitor many channels at the same time and read all the signals in one place.
I use NEON Wallet, you could store, receive, and send NEO and GAS. The awesome thing about it is that you can claim your automatically generated GAS if you hold NEO cryptocurrency in the NEON Wallet.
Some Promising Coins you should invest: Naga - coin comes with a strong tokenomics behind. The company went for an IPO earlier in German Stock exchange Ark seems to be a very promising cryptocurrency to invest in at the moment. it is trading around $3.94. Siacoin - a decentralized cloud storage platform Monero isn’t exactly new to the markets, but it is one of the early altcoins with a strong emphasis on anonymity.
I recommend you about the wallet i love so much. It is Jaxx- a multiplatform multicurrency wallet. The private keys are stored on your device. It has a beautiful UI, is really sleek and easy to use, and has shapeshift built in. What's great about Jaxx is that it supports every major platform. Desktop clients available for Mac, Windows and Linux. Mobile clients available for iOS and android, and hardware wallet support coming soon.