A good start would be to design your base with protection in mind, use a good building that has few entrances and tight combat hallways, Always use props with large amount of health to protect against explosives such as containers or prison archways. Some good weapons to defend with would be Thunder guns(15m), Minigun 2.0's(250m) or Gluon guns(250m). Thunder guns would be the cheaper option for someone in your footsteps, I should highly recommend getting a combat suit as quickly as possible to help you defend.