I love my android phone and it is always cheaper to buy outright than to take out a contract.
To answer your question, pussyfoot. There are two ways of buying a phone - on contract (normally 2 years) or buy outright. A contract will include phone minutes, texts and a data allowance that connects the phone to the internet when wifi is not available.
If you buy your phone outright then you will need a SIM card that gives you minutes, texts and data every month. You can do this on a fixed contract, a rolling monthly contract which can be cancelled any time without penalty or pay as you go.
If you buy the phone outright you can shop round for the best SIM card for you - the phone is unlocked (not tied to a service provider) and there are many to choose from. I pay £7 a month but plans are available from £5 a month.
You do not need an iPhone for your modest needs - it would be like buying a Rolls Royce just to take your rubbish to the tip once a year :)
Nor do you need a huge amount of data. I suggest 1GB a month would be more than enough without worrying about running out towards the end of the month.
Go to any shop and have a good look at the Android phones (do not buy a Windows phone) and decide which size screen will suit you best. I like a 5.5" screen but many people do not like a large phone.
In the meantime you can have a look at the plans that will give you the call minutes, texts and data. The Plusnet deal at the top of the page looks excellent value at £6 a month on a rolling monthly contract with 2GB data and 1000 phone minutes.
https://www.uswitch.com/mobiles/compare/sim_only_deals/?gclid=EAIaIQobChMIvPqGmpze1gIVExMbCh1iagAhEAAYASAAEgKoOvD_BwE
This is a great starting point for the choice of Android phone
http://www.techadvisor.co.uk/test-centre/mobile-phone/best-budget-phones-for-2017-3473395/
If you are happy with your current phone then an alternative would be a tablet for browsing the net. Amazon has a 7" cheapie for £50
Amazon.co.uk User Recommendation
You would need a data only plan for a tablet - I pay £4 a month.
There are other tablets available - if you think a tablet could be the answer, look at other options before buying.