Welcome, 57 here & I airsoft to kinda justify my collection, I don't get to play often but when I do... It's great fun, bit of a heifer so it's also knackering.
Take plenty of fluids with you & wear suitable boots, as the above comments have said, don't buy until you get your UKARA then if you decide to play a lot buy the best you can afford (even <£100 pews can perform well), if you're gonna collect then buy what you fancy. Try as many different flavours as you can until you decide if you like AR's, AK's, Bullpups, SMG's, Modern, Retro etc but avoid Gas until you have a bit more experience.