i could use some help

[SSJHarlee]

So next school year i am joining my high schools jrotc program and i would like to get better at my calisthenics before i join. What do you think the best calisthenics routine would be to start? Im pretty weak so i can not do any advanced workout routine. i would like to gain some muscle and endurance from the routine if thats possible. I have a little over 2 months before i join, so im trying to make the most out of the time i have but im not sure where to start. Thank for the help.