Before a spin
Check the total stake shown for one spin. On games with selectable lines or ways to win, the displayed total matters more than the value attached to a single line. Open the help or paytable before you play: it explains qualifying symbol combinations, feature rules and the value of any prizes.
There is no prize for knowing every term at once. Read the sequence and give yourself permission to stop at the point you have understood.
Random outcome, not a pattern
The Gambling Commission distinguishes fully random machines from compensated machines. Fully random games keep the chance of each outcome constant, while a compensated game may vary the chance of a prize in response to earlier results. In both cases, the game information, not a recent result, is the proper source for understanding the machine you are about to use.
A table can be watched before it is joined, which is often the easiest way to see how the written rules meet the pace of play.
RTP in context
Return to player, or RTP, is a long-run percentage rather than a promise about a visit. The UK Gambling Commission explains that it is measured over many plays; it does not mean that a £1 stake returns a fixed amount in one session. Set a money limit and a stopping time before you begin.
If you decide to see the game in person, check current entry, access and timetable information with the venue before you travel. Keep those arrangements separate from your gambling budget.
If the machine gives an RTP figure, treat it as a long-run measure across many plays, not a prediction for your own session.