Conferences are a good way to meet people in your field, learn about current research, and hone your own research. Consider presenting at one conference per year. Trust me, doing more than that can be too much added stress and work.
Most conferences list a call for papers on their website. You can either submit straight to the conference or to a panel that you think your paper would fit. You are usually required to submit a 250 word abstract and some require that you also submit a CV. There are a few that require you to submit your paper before attending the conference.
Most universities have some kind of funding for travel to conferences. Seek out information from your department. Additionally, conferences offer travel grants to graduate students. Deadlines for these grants can be early so make sure you read everything about the conference and write down any deadlines.