salam
i think it is great that you have been offered books for free and that you also have read the shahadah and i think disconnecting from the previuos church may be hard howeva you can overcome this or else you may go for the good and if they tell you to commit sins just think of allah and refuse if possible
hmm i think it is not a good idea to tell your mother that you are a muslim but however since you say she has hints of islam perhaps you could persuade her into islam with proven miracles in islam proven by science and ask her about her knowledge in islam and maybe you could convince her however just remember that she may find it curious and may suspect something so you may consider keeping low and i would not conisder telling other members unless your mother knows and approves because if your mother knew and approved then you would have backup in case of arguments (not that im saying there are any)
is there any chance you could travel to other mosques elsewhere via bus or car or could you not ask one of the local muslim brothers .i think that it is great that you want to perfect your salah before praying five times a day in that way you will get more good deeds and your salaah will be accepted
i also think that if your church did find out you could tell them that that is not true and you could tell them why you became a muslim and you could say that this is the one and only true religion(only do this if its appropriate)wa
wasalam
محمد طيب