so do I
it now costs me £9.99 a month, I have a stocks and shares ISA. They put the monthly payment towards any share dealing charges, so I find I never pay any. I reinvest the dividends at intervals when they reach a worthwhile amount. You can transfer previous years' cash ISAs in if you want.
The ISA means I have no tax to pay or to declare.
They also offer a self-select SIPP Pension scheme, you get a tax rebate into it at standard rate for whatever you contribute. I have one, It costs an additional £10 a month.
If you are an inexperienced or cautious investor, best advice is usually to buy a very low cost tracker fund. Almost no active fund managers beat the index long term. Of the few that do, you won't know who they are going to be until it's too late. Indices will not go up like a rocket, but neither will they fall like the stick. You can put aside a small percentage of "fun" money if you don't mind it going down the drain. If you self-manage a fair number of solid stocks, you will likely end up with a tracker-like portfolio of your own. If you go for adventurous or fashionable stocks then occasionally you will do much better, but usually you will do much worse.
Over the last 5 years or so my European investments have done much better than UK and US. IMO the Brexit catastrophe will continue to shackle UK growth for the foreseeable 10 years or so, though you may disagree. Ask Rees-Mogg.
I don't currently have a UK tracker in mind, but this European one seems quite good.
https://markets.ft.com/data/etfs/tearsheet/summary?s=VERX:LSE:GBP
Since Referendum Day it's gained over 36% plus dividends. The UK FTSE has gained nearly 2% over the same period. I can't think why.