Technology... It's proving to be a challenge for me

Good morning steem. So I got an early start on the day and I'm back to trying to figure out the ins amd outs of buying and selling crypto. more specifically I want to start out with steem.

Now I consider myself of average intelligence but I appear to be really lacking in the modern technology department. I think I heard windows 98 calling for me to come back.... So thanks to a very informative post here on steem I've learned this much.

1. What a block chain is and somewhat how it works.
2. In order to buy steem you have to buy Bitcoin first.
3. I need to have at least 2 crypto wallets .
4. Well there is no 4 yet..

I guess the challenge for me is because I'm on the go so much and while I do quite a bit of work on a computer it's a work computer and not really appropriate to be buying crypto on so I rely on my phone almost entirely for my personal internet needs. So I will ask you all for some opinions and advice. Any help is appreciated.

1. Can I do this all off of my phone?
   2 If I can what do you all use? It seems to me that using coinbase.com from a computer is decently easy.
2. What's the easy method you all have found for converting fiat to crypto and then back again ?

Thanks for any help I get.