Yes, lay Buddhists can attain enlightenment and Buddhahood by practicing what the Buddha taught. The difficulties might be the fact that monks can devote their whole life to the practice, and lay people have the stress of everyday life to deal with.
By the way, this is off topic, but there are some people on here who claim to be Buddhists but are saying false things that go against the Buddhas teachings, such as saying reincarnation is not real when Buddha taught it was. They’ll only confuse you, so stick with reputable Buddhist sources.
Well, I would imagine that most can, but won’t as they are lay Buddhists, and many of them are Buddhist only because it is their culture, not because they actually desire to become Buddhas. I think that the Buddha taught that anyone can become a Buddha, they need not necessarily be a monk. The Buddha Himself became one on his own, and was not a monk.
So to answer your question, yes, they can, but only if they really have that as their motive.
“This mind is the Buddha. I don’t talk about precepts, devotions or ascetic practices such as immersing yourself in water and fire, treading a wheel of knives, eating one meal a day, or never lying down. These are fanatical, provisional teachings. Once you recognise your moving, miraculously aware nature, yours is the mind of all buddhas. Buddhas of the past and future only talk about transmitting the mind. They teach nothing else. If someone understands this teaching, even if [she’s] illiterate [she’s] a buddha. If you don’t see our own miraculously aware nature, you’ll never find a buddha even if you break your body into atoms.”
Yes it is possible… You would do it the same way that a monk would do it. By following the Noble Eightfold Path and doing your insight meditations. The only difficulties you will come across is the fact that you will have to work in order to pay for food and things like that and so have a greater chance of becoming materialistic and giving into your cravings which is not good for the path to Buddhahood… Good Luck I envy you I wish I had the resolve to commit myself to that.
Its hard work and takes a dedication. If you are truly seeking this goal the way will be revealed to you.
“When the student is ready the teacher will come.”
If a step along the path is not the correct one then that step will somehow be thwarted or prevented.
Just remain aware and keep up your mediation work.