I've got bases with large radar in North America and Central Asia, but I'm not really getting hardly any UFOs. The lack of Alien Alloy and Elerium is killing me. I'm playing on Beginner mode. Is this normal behavior for an Xcom game? I've never noticed this problem in Dos Xcom. I've only shot down 2 UFOs in the entire game (one was a small scout, yay 1 alloy!), and it's already beginning of May. The few others I did happen to spot left my radar too quickly or outran my interceptors, but they're few and far between, I can go days, even an entire month without spotting one and just having to do terror missions.
Is my game bugged or is this normal or what? Am I screwed in the late game if this continues? I really need Elerium.
I'll try not to spoil too much of the game but yes, what you describe is normal for two reasons.
First reason is that the aliens only send 1 random mission (Research, Abduction, etc.) each month, besides terror missions. During the first month that mission is hardcoded to be at the location of your 1st base, but afterwards it can be a random location anywhere. Terror missions are additional to this random mission and you'll get 1 of them each month. If you check the graphs for alien activity like NoelBuddy has mentioned you'll see where those missions took place so far.
Second reason is that your radars don't automatically detect UFOs once they get in range (unlike the Hyperwave Decoder), so you can detect UFOs right at the moment where they are about to leave, making interceptions impossible.
The good news is that after a certain date the aliens will start sending 2 random missions (plus the Terror one), so your chances of detecting UFOs will be doubled. But the best way to ensure UFO detection during the first months is really to increase radar coverage by building more bases as Arthanor has described.
But if you are getting unlucky during those first months and the UFOs are being generated on the opposite side of the world, there's a tactic you can do. After the 1st week check the Alien Activity graphs to see where UFOs have been operating for that month. Then send a Skyranger loaded with a combat squad for that location and put it on patrol until it rans out of fuel. If you're lucky it may be able to detect any UFOs that enter its detection range, and you can either try to get your Interceptors to reach the UFO on time or assault it with the Skyranger if it lands.