Alright starting point for your research - and I'm being fairly nice, everyone else hates when someone comes in and asks these pre-beginner questions - you're not even really a beginner because you haven't done any research.
Yes, testosterone is the best thing to start with; it will be included in all future cycles you do as well. When you use testosterone or any anabolic/androgenic steroid, you body stops producing its own testosterone, so you need to have testosterone in your cycle to function correctly.
400mg/wk is fine for a first time. Run it for 10 to 12 weeks. Use a long estered testosterone, so Testosterone Enanthate or Testosterone Cypionate. Inject 200mg twice a week - I prefer Sunday Morning at 8am and Wednesday night at 8pm - splits the week perfectly in two and keeps blood levels fairly stable. During this time period, I would also recommend using HCG - look it up - at 250iu twice per week (500iu total) - inject it at the same time as your testosterone, but in a different syringe. HCG will keep your body sending signals that result in the production of your natural testosterone so when you stop, you will have an easier time keeping your gains and getting your body to produce its natural testosterone again.
You need to do some research now on Post Cycle Therapy for when you stop using the testosterone. During the 10-12 weeks you are using Testosterone, your body will shut down its own production of testosterone. Afterward, you need to help it start up again. Two weeks after you last shot, a majority of the exogenous (injected) testosterone will be out of your system and you will need your body to start producing its own again. Look up proper PCT protocols... I don't do it anymore because I am permanently on testosterone (200mg/wk) because my body produces very little of its own. This will involve one or both of the following compounds, Clomid (clomiphene) and Nolvadex (tamoxifen).
A typical protocol i've seen run is this:
Weeks 1-10 Test E or Test C, 400mg - 500mg per week
Weeks 1-10 HCG 500iu per week
Weeks 1-14 Arimidex .5mg EOD
Weeks 12-14 Nolvadex 40mg/day or Clomid 150mg/day
Weeks 14-16 Nolvadex 20mg/day or Clomid 50mg/day
Weeks 12-16 Nolvadex/Clomid 20mg/50mg per day
As I said, look up what they are doing concerning PCT nowadays, but that lays out the time frame for you.
Hope that helps, you might get flamed for asking these question without any research and I might get flamed for helping you. But I had some free time so I hope that helps.