Hey goosebaby, I've been to several skirmishes already so im fairly new go to airsoft as well.
Most people would agree that AEG's (automatic electric gun) are by far the best as they're widely available, consistent shooting (unlike gas blowbacks where shots become weaker due to change in gas pressure) and you can find many good brands out there for aeg's such as g&g.
But your choice of gun depends on your play style, for aggressive CQB you'd obviously go for a short barrelled carbine or pdw (mp5 ump etc) general use in all situation you'd want an assault rifle (m4's are the most popular and most available, the components and spare parts can be found easily online). You'd be best with AEG's for these type of weapons.
If you're looking for a sniper rifle, I believe the spring versions are generally more powerful accurate and reliable because of its fairly simple mechanisms.
For a beginner rifle, look up the "cm16 raider l" by g&g this comes at around £130 and I've seen many positive reviews on this rifle. It's an m4 variant and comes with RAS (rail adapter system which allows you to customize your weapon with attachments e.g laser sights and optics)
One thing to note is that in order to purchase these airsoft weapons in there real colour (black, tan/coyote brown) uk retailers will ask for your UKARA number which is a membership thing that you can get after playing 3 skirmishes within the space of 2 months (don't quote me on that) This membership basically allows retailers to avoid selling realistic weapons to people without a legitimate reason for purchasing. You have to be over 18 to apply. Otherwise you have to purchas in two tone which costs £15 ish and the retailers spry the weapon in a bright colour. This is unavoidable unfortunately.
In terms of gear, just where anything that's comfortable. Equipment wise, a decent pair of boots that are comfortable to run in, you may decide to purchase a chest rig but these can be really expensive (over £150) and the cheaper ones are generally less quality knock offs.
Though im still fairly new to airsoft, I hope this helps.