Starting investing for 21 year old

[fitflop]

My son is about to turn 21 and I would like to open him a stock and shares account to just get him going.

I can only afford £500. I was thinking of a AJ Bell stocks and shares ISA in moderately adventurous but then i’m not sure due to his age and as it’s a long term savings account whether I should pick adventurous. He has a cash LISA with moneybox so I’m thinking stock and shares ISA over a dealing account. I don’t have any experience of this sort of thing so any ideas please?

A few queries...
How much does your son have in cash savings?
What is his current situation regarding income and supporting himself?
Will the account be in his name with unfettered access?
How good are his money management skills?
You say you don't have any experience with this sort of thing, so this leads me to suspect he doesn't either...?

Thank you very much for your reply.
He has put the max into his LISA since he was 18.
He has around £5k in everyday savings.
He has a 8% interest account where he saves the max £200pm for one year.
He has a 5.15% interest account he saves the max £50pm for two years.
He works full time, lives with us and pretty much supports himself.
He gives me rent which I generally save for him and he is then given this to pay the £4k each year into his LISA.
This account would be managed fully by him and I would expect him to top it up each month by £50-£150
I think I’m fairly financially savvy but have no experience of stocks and shares. I don’t want this for my kids as a good pension is likely to be harder to come by and I want him to build up a savings nest egg.

I hope he is contributing (hopefully max matched amount) into his work place pension as well. Start doing that at a young age and a good retirement will be possible

If this is for long term investments then perhaps look for a low cost global index fund such as Vanguard FTSE Global All Cap, or S&P 500 tracker.

I’m not a financial adviser, so just my own ideas. I'm not a fan of managed funds.
Three reasons -

They rarely beat the index over the longer term (read up on Warren Buffet’s million dollar bet with hedge funds in 2008).

Higher fees depress growth over the longer term.

The name of the fund can be somewhat misleading - adventurous funds are often still rather conservative in their approach as they can include a significant percentage of bonds- this smooths out volatility (the ups and downs of short term swings in the price), but over the longer time frame returns are often disappointing. (I dont know about the AJ Bell fund).

If your son is investing for the longer term 10-20 years or more, short term volatility is not a factor that need trouble him - this is the advantage of investing from early on in your career. You can weather all sorts of stock market upheavals if the growth is on a good upward trend over time.

If you look on Trustnet you can investigate the fund in detail and pop it in the basket along side a global fund and S&P 500.
Then use their multi tools to compare past performance over a long time frame. You don’t need to register to do this.
Of course past performance is not an indication of future outcomes and all investing carries risks.

I would also suggest your son looks carefully into his pension arrangements. What benefits are his employers offering? Which funds is it invested in - the providers default fund is often not the best option. If there is an opportunity to choose his own funds, I would encourage him to do some research and establish a set up suitable for his age.

I would also add - never ever invest in something you don’t understand, always diversify your assets and undertake your own research.