Hi there,

First and foremost welcome to Steemit,

We are glad to have you here.

Secondly the answer to your question is there are no specific wallets for all Altcoins.
Yes some hold a variety like coinimi and many others however the best recommendation is to download each wallet directly from the original source and one everything is synced (note some wallets can take hours) then transfer your coins into those wallets.

Safest option.

Or just use things like Coinbase, for Etheruem light coin and Bitcoin. Recently the token card was released so if you can get your hand on their debit card they store several coins. I've yet to use it but it's quiet user friendly.

Have a look around read a lot of forums but agoid exchanges unless you got security right at it's peak but that's at your own risk.

Happy investing.
Hope we can connect and welcome once again.