You can put almost anything you want in your log book. The only issue is claiming time that does not apply. No harm in putting in trial flights or sim rides as long as you remark they were "leisure flights" for example and don't include them in the total time for that page.
As for the sims, the only relevance of sim time is 100 hours towards your ATPL (in the UK). As long as this particular sim time is not counted toward that (should you train for your ATPL) then you are doing nothing wrong.
Remember that whilst a log of flights is required, your logbook is your Personal flying log which just happens to store your flights in a required format. Only if you claim to have something you don't are you commiting an offence.